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Gate Globe Check
Core manual valve theory, design, standards, materials, trims, and field application. The structural backbone of industrial piping β isolation, regulation, and protection.
If ball and butterfly valves dominate modern automation, gate, globe, and check valves still form the structural backbone of industrial piping systems. They are mechanically simple, highly repairable, tolerant of extreme pressure and temperature, and trusted in services where failure has consequences.
These valves define how engineers think about isolation vs regulation, pressure drop vs control, manual vs automatic behavior, and maintenance philosophy. Every other valve type borrows concepts from these three.
This page integrates the governing standards framework (API, ASME, ASTM, MSS, NACE), body materials, the API trim number system, hardfacing, bolting, and end connections into a single comprehensive reference. For the complete standards framework, see Valve Standards β. For the full materials and trim reference, see Valve Materials & Trims β.
Standards Framework β How Gate, Globe & Check Valves Are Governed
No single standard fully governs these valves. API defines type and behavior. ASME sets the pressure-temperature envelope and dimensions. ASTM defines materials. MSS fills the testing and marking gaps. NACE overlays sour service restrictions.
- API 600 / 602 / 603 / 594 β Valve type, construction, and performance intent
- ASME B16.34 + B16.10 + B16.5 β Pressure-temperature ratings, face-to-face dimensions, flange interface
- MSS SP-61 + SP-25 β Pressure testing methodology, marking and traceability
- ASTM A216, A351, A182, A350, A890, etc. β Body, trim, and bolting material specifications
- NACE MR0175 / MR0103 β Sour service material restrictions when applicable
| Valve Type | Primary API Standard | Mandatory ASME Overlay | MSS Overlay | Fire Test |
|---|---|---|---|---|
| Gate β OS&Y, Bolted Bonnet | API 600 (14th ed. 2021) | B16.34, B16.10 | SP-61, SP-25 | API 6FA (if required) |
| Gate / Globe / Check β Forged β€4" | API 602 (11th ed. 2022) | B16.34 | SP-61, SP-25 | API 6FA (if required) |
| Gate β Corrosion-Resistant | API 603 (10th ed. 2025) | B16.34 | SP-61, SP-25 | API 6FA (if required) |
| Check Valve (Wafer/Lug/Flanged) | API 594 (9th ed. 2022) | B16.34, B16.10 | SP-61, SP-25 | API 6FA (if required) |
| Testing Baseline (all types) | API 598 (11th ed. 2023) | β | SP-61 | β |
- API 600 (14th ed. May 2021) β Bolted bonnet steel gate valves: heavy-wall, OS&Y, rising stem with backseat. The definitive refinery and pipeline gate valve standard. Always paired with ASME B16.34 and API 598.
- API 602 (11th ed. May 2022) β Compact forged steel gate, globe, AND check valves (typically β€4"). Forged body, socket weld / threaded / flanged ends. Covers all three valve types in one standard.
- API 603 (10th ed. July 2025) β Corrosion-resistant gate valves: reduced wall thickness vs API 600, optimized for stainless alloys. For API 603 specifically: must still comply with ASME B16.34 β reduced wall does not mean reduced P-T rating, it means the material group (stainless) allows thinner walls to achieve the same rating.
- API 594 (9th ed. Feb 2022) β Check valves: wafer, lug, flanged, and butt-weld. Covers swing, dual plate, lift, and tilting disc types. Includes P-T ratings, face-to-face dimensions, and testing per API 598.
- API 598 (11th ed. 2023) β Mandatory testing baseline for all API valve types: shell pressure test, seat leakage test, test pressures, test durations, and acceptable leakage quantities. Referenced by API 600, 602, 603, 594, 608, 609. If a vendor's test cert does not reference API 598, the test is likely non-conforming.
- API 574 β Inspection practices for piping system components including valves. Used by plant inspectors and reliability engineers during in-service inspection.
- API 6FA (5th ed. May 2020) β Broad fire test applicable to all valve types. Required when fire-safe certification is specified on gate, globe, or check valves. Not API 607, which is limited to soft-seated quarter-turn valves.
- ASME B16.34 (2025) β The core valve pressure-body standard. P-T ratings, material groups, minimum wall thickness, stem retention (anti-blowout), and end connection rules. Pressure class alone is NOT the operating pressure β always verify against the B16.34 P-T table for the specific body material at operating temperature.
- ASME B16.10 (2022) β Standardized face-to-face and end-to-end dimensions. Critical for turnaround interchangeability. Not every valve is built to B16.10 by default β verify on the datasheet.
- ASME B16.5 (2025) β Pipe flange dimensions, P-T ratings, bolt patterns, facing type. Governs flanged gate, globe, and check valve connections up to NPS 24. Large-diameter flanges (NPS 26+) fall under ASME B16.47.
- ASME B16.11 (2021) β Forged fittings for socket weld and threaded small-bore valve connections. Class 2000/3000/6000 β not the same as Class 150/300/600 flanges.
- ASME B16.20 (2023) β Metallic gaskets: spiral wound, RTJ oval/octagonal rings, metal jacketed. Wrong spiral wound selection = chronic body joint leaks.
- ASME B31.3 (2024) β Process piping code: governs how valves are installed, tested, and accepted in refinery and chemical plant piping systems. B31.3 governs the piping system, not the valve design β yet controls installation, examination, and pressure testing of the complete assembly.
- ASME B31.1 β Power piping code. Used for steam systems and boilers where gate and globe valves dominate.
- MSS SP-25 (2018) β Marking requirements: size, class, material grade, heat number. Marking must match CMTR at incoming inspection β a stamp without a matching CMTR is grounds for rejection.
- MSS SP-61 (2019) β Pressure testing of valves: shell test and seat test logic. Often paired with API 598 or referenced as the testing basis in client specifications.
- MSS SP-117 (2023) β Bellows seal valves for fugitive emissions control. Specifying bellows seal bonnet on globe valves eliminates packing as a VOC emission path.
- BS 1873 (1975) β Steel globe valves: legacy standard used in BS-preference projects. Overlaps with API 602 in scope.
- BS 1868 (1975) β Steel check valves: legacy standard for BS-based projects, overlapping API 594.
- NACE MR0175 / ISO 15156 β Materials for upstream HβS service. Governs body material grades, heat treatment, and hardness limits for all wetted components including gate, globe, and check valves.
- NACE MR0103 / ISO 17945 β Refinery wet HβS conditions. Different rules from MR0175 β do not conflate. Refinery gate and globe valves in sour hydrocarbon service fall under MR0103, not MR0175.
Body & Bonnet Materials
Body material determines pressure containment, corrosion resistance, temperature capability, weldability, and cost. ASME B16.34 ties each ASTM material group to its allowable P-T envelope. Gate and globe valves are typically cast (large sizes) or forged (small bore and high pressure).
| Material | Common Name | ASTM Cast | ASTM Forged | Typical Gate/Globe/Check Service |
|---|---|---|---|---|
| WCB / A105 | Carbon Steel | A216 WCB | A105 | General hydrocarbon, steam, utilities β the default |
| LCC / LF2 | Low-Temp Carbon Steel | A352 LCC | A350 LF2 | Cold service, cryogenic-adjacent β mandatory Charpy impact testing |
| WC6 / F11 | 1ΒΌ Cr-Β½ Mo | A217 WC6 | A182 F11 | Elevated temperature β steam, power generation |
| WC9 / F22 | 2ΒΌ Cr-1 Mo | A217 WC9 | A182 F22 | Higher temperature and pressure β refinery heaters |
| CF8M / F316 | 316 Stainless Steel | A351 CF8M | A182 F316 | Corrosive service β chemical plants, acid systems |
| CF8 / F304 | 304 Stainless Steel | A351 CF8 | A182 F304 | Mild corrosive service β lower cost than CF8M |
| Duplex (F51) | 2205 | A890 CD3MN | A182 F51 | Chloride service β offshore, coastal, chemical |
| Alloy 20 | β | A351 CN7M | B473 | Sulfuric acid and phosphoric acid service |
| Monel | β | β | MFG standard | Marine, HF acid β seawater and aggressive corrosion |
A216 WCB and A105 are NOT suitable for low-temperature impact-critical service. They have no mandatory Charpy impact testing requirement. A352 LCC (cast) or A350 LF2 (forged) are required for cold-service gate and globe valves. This is the most common body material procurement error on cold-climate and cryogenic projects.
Shared Mechanical Architecture (Gate & Globe)
Before separating gate and globe valves, understand what they share. Most real-world failures happen in the shared components, not the closure element.
Pressure Boundary Components
Body
The primary pressure-retaining component. Material choice (carbon steel, alloy steel, stainless) is driven by pressure class, temperature, corrosion allowance, and code. ASME B16.34 governs minimum wall thickness.
Bonnet
Provides access to internals and seals the body opening. Bonnet design directly affects pressure rating, fugitive emissions performance, and serviceability.
BodyβBonnet Joint
A major leak risk. Design options: bolted gasketed joint, welded joint, and pressure seal joint. ASME B16.34 governs the design envelope for each.
Bonnet Designs and What They Signal
Bolted Bonnet
Most common. Serviceable. Gasket is a maintenance item. The default for most industrial gate and globe valves. Governed by API 600 / 602 and ASME B16.34.
Welded Bonnet
Excellent for fugitive emissions control. Reduced serviceability β internals cannot be accessed without cutting. Common in API 602 forged steel valves and small-bore high-pressure service.
Pressure Seal Bonnet
Used in Class 900 and above. Internal pressure energizes the seal β higher pressure produces tighter sealing. Lighter than the massive bolting required at high class. Common in power generation gate and globe valves.
Bonnet choice often tells you what pressure class and service severity the valve was designed for. Pressure seal bonnets are a direct signal of Class 900+ service.
Stem, Packing, and Fugitive Emissions
Stem
Transmits operator force to the closure element. Subject to axial load, bending, and corrosion. ASME B16.34 requires anti-blowout stem design β the stem cannot be ejected under pressure.
Packing
Primary fugitive emission path. Requires adjustment over valve life. Material choice affects torque and leakage. For fugitive emissions compliance: ISO 15848 or API 624 testing may be required depending on the project spec.
Backseat
Allows packing replacement under pressure (with valve fully open). Not a substitute for proper isolation β commonly misunderstood and misused in the field. Defined and required by API 600 and API 602.
1. Gate Valves
Isolation valves by geometry, not force. The default choice for large-diameter isolation with minimal pressure drop.
- API 600 (14th ed. May 2021) β Heavy-wall bolted bonnet steel gate valves: OS&Y design, rising stem with backseat, flexible wedge standard. The definitive standard for large refinery and pipeline gate valves. Requires ASME B16.34, B16.10, and API 598 overlay.
- API 602 (11th ed. May 2022) β Compact forged steel gate valves β€4": socket weld, threaded, or flanged ends. Also covers forged globe and check valves. Requires ASME B16.34 and API 598 overlay.
- API 603 (10th ed. July 2025) β Corrosion-resistant (stainless) gate valves: reduced wall thickness vs API 600, optimized for CF8M and other stainless alloys. Used in chemical plant and corrosive service. Requires ASME B16.34 and API 598.
- API 6D (25th ed. 2021) β Pipeline gate valves when specified in transmission service. Gate valves under API 6D are often slab or expanding gate design β fundamentally different from API 600 wedge-gate valves.
- API 598 β Mandatory testing for all gate valve types: shell test, seat leakage test (zero leakage for metal seat per API 598 Class A), and test durations.
- ASME B16.34 β P-T ratings, wall thickness, stem anti-blowout β always required alongside any API gate valve standard.
- MSS SP-25 + SP-61 β Marking (heat number / CMTR traceability) and pressure test method details.
- API 6FA β Fire test when fire-safe gate valves are specified. API 607 does not apply to gate valves.
- NACE MR0175 / MR0103 β Sour service material and hardness requirements where applicable.
1.1 What a Gate Valve Is Actually Doing
A gate valve uses a sliding closure element (wedge or parallel plate) that moves perpendicular to flow. When fully open, the gate is completely out of the flow path β turbulence is minimal and pressure drop is very low. This makes gate valves ideal for large-diameter isolation service.
1.2 Why Gate Valves Fail When Throttled
Gate valves are frequently misused as throttling valves. When partially open: flow jets impinge on the lower edge of the gate, turbulence induces vibration, seats erode rapidly, and the gate chatters and damages guides. This is not a design flaw β it is a misapplication.
If you need to control flow rate, use a globe valve or control valve. A gate valve held mid-stroke will destroy itself in months β often faster. API 600 construction is optimized for fully open and fully closed dwell β not modulation.
1.3 Gate Valve Closure Designs
Wedge Gate
The most common design β API 600
Wedge angle produces sealing force. Tighter closure increases seat stress. Sensitive to thermal expansion.
Variants:
- Solid wedge β strong but prone to thermal binding
- Flexible wedge β tolerates thermal growth; standard in API 600
- Split wedge β self-aligning, best for high-temperature service
Used in: steam service, refinery block valves, utility isolation.
Parallel Slide Gate
No wedging stress
Two parallel plates seal against seats. No wedging stress, reduced thermal binding, stable sealing across temperature swings.
Common in: steam, power generation, high-cycle isolation.
Resilient-Seated Gate
Elastomer-seated water service
Elastomer seats provide excellent shutoff at low pressure. Temperature limited. Intolerant of debris or hydrocarbons.
Used in: water, wastewater, utility systems. MSS SP-70 (cast iron) or AWWA standards typically govern water service gate valves.
Knife Gate
Cuts through solids and slurry
Thin blade cuts through solids. Not designed for pressure-tight shutoff in high-pressure service. Often unidirectional. Not governed by API 600 β typically MSS SP-81 or manufacturer standard.
Used in: mining, pulp & paper, sludge service.
1.4 Gate Valve Trim β Materials and API Trim System
Gate valves use the API trim number system (Trim 1β18) to define the material combination of seat, disc/wedge, stem, and backseat. One trim number on a datasheet replaces a paragraph of material callouts β provided both parties read the same version of the standard.
| Trim # | Nominal | Seat | Wedge / Disc | Stem / Backseat | Typical Gate Valve Service |
|---|---|---|---|---|---|
| 1 | 13Cr | 410 SS | 410 SS | 410 SS | General service |
| 5 | FHF (13Cr) | Stellite hardfaced | Stellite hardfaced | 410 SS | Severe wear, steam |
| 8 | 13Cr + HF | Stellite hardfaced | 410 SS | 410 SS | General hydrocarbon β most common gate valve trim |
| 10 | 316 | 316 SS | 316 SS | 316 SS | Corrosive service |
| 12 | 316 + HF | Stellite hardfaced | 316 SS | 316 SS | Corrosive + erosion |
| 13 | Alloy 20 | Alloy 20 | Alloy 20 | Alloy 20 | Acid service |
| 16 | FHF (316) | Stellite hardfaced | Stellite hardfaced | 316 SS | Severe corrosive / erosive |
| 17 | FHF (347) | Stellite hardfaced | Stellite hardfaced | 347 SS | High temp + erosion |
1.5 Gate Valve Bolting
| Body Material | Standard Service Bolting | Sour Service | Low-Temp Service |
|---|---|---|---|
| Carbon Steel (WCB / A105) | A193 B7 / A194 2H | A193 B7M / A194 2HM | A320 L7 / A194 7 |
| Cr-Mo (WC6 / WC9) | A193 B16 / A194 4 | A193 B16 / A194 4 (verify per spec) | Not typical β high-temp alloy |
| 300-Series SS (CF8M) | A193 B8M / A194 8M | A193 B8M / A194 8M | A193 B8M / A194 8M |
| Duplex (F51) | A453 Grade 660 or per project spec | Confirm MR0175 compliance per spec | Per project spec |
1.6 Selection Reality
Choose Gate When
- Line size is large
- Pressure drop must be minimal
- Valve will stay open or closed for long periods
- Pigging is required (full bore)
Avoid Gate When
- Throttling is required
- Frequent cycling is expected
- Tight shutoff at low pressure with debris present
- Automation is required β high thrust and long stroke make gate valves expensive to automate
1.7 Gate Valve Actuation
Gate valve actuation converts rotation to linear motion via stem threads. The actuator must overcome seat friction, packing friction, stem thread friction, differential pressure forces, and wedge geometry effects. Thrust requirements are highest at final closure.
A gate valve closed at high temperature, then cooled β the body contracts around the wedge, and required opening thrust may exceed actuator capability. Mitigated by flexible or split wedges, oversized actuators, and operator training not to overtighten gate valves hot.
Manual Handwheel
Small sizes. Low pressure. Infrequent operation.
Gear Operators
Large diameters. High thrust. Reduce operator effort at large sizes and high pressures.
Electric Actuators (MOV)
Precise positioning. High thrust. Thermal binding is a key sizing input. AUMA, Rotork, Limitorque type.
Hydraulic Actuators
Extremely high thrust in a compact package. Used for ESD, pipeline, and large-diameter service. Common for API 6D gate valves.
- Size thrust for maximum ΞP, aged seat friction, and thermal effects β not catalog torque
- Electric or hydraulic actuation preferred β pneumatic air struggles to deliver sustained thrust at gate valve scale
- If the actuator fails, the valve fails β treat gate valve and actuator as one system
2. Globe Valves
Valves built to waste pressure on purpose. The mechanical basis of most control valves. The go-to choice wherever throttling stability matters more than efficiency.
- API 602 (11th ed. May 2022) β Primary standard for forged steel globe valves (β€4"). Same standard covers forged gate and check valves. Socket weld, threaded, or flanged ends. Always paired with ASME B16.34 and API 598.
- API 598 (11th ed. 2023) β Mandatory testing: shell pressure test, seat leakage test. Globe valves with metal seats must meet API 598 Class A seat leakage (zero leakage). Soft-seated globe valves use Class B (rated leakage).
- ASME B16.34 (2025) β P-T ratings, wall thickness, anti-blowout stem requirement. Always required.
- ASME B16.10 (2022) β Face-to-face dimensions for interchangeability. Critical on turnarounds where a replacement globe valve must fit the existing spool.
- BS 1873 (1975) β Legacy steel globe valve standard used in BS-preference specifications. Overlaps API 602 in scope for forged globe valves.
- MSS SP-117 (2023) β Bellows seal globe valves for fugitive emissions control. Eliminates packing as an emission path. Required on some process streams under environmental regulation.
- API 6FA β Fire test for globe valves when fire-safe certification is specified. API 607 does not apply to globe valves.
- NACE MR0175 / MR0103 β Sour service material requirements. Globe valves in wet HβS service require NACE-compliant body, trim, and bolting β each verified by CMTR.
- ISO 15848 / API 624 β Fugitive emissions qualification testing for packing systems. Required when VOC emissions compliance is specified.
2.1 Operating Principle
A globe valve forces flow to change direction as it passes through the valve. The disc moves toward or away from a seat, regulating flow area gradually. This creates predictable flow control, high pressure drop, and excellent throttling stability.
2.2 Flow Direction and Control Behavior
Globe valves are usually directional. Correct flow direction stabilizes the disc, reduces vibration, and improves control. Incorrect flow direction causes chatter, accelerates seat wear, and increases stem load.
Always verify flow direction before installation. An arrow on the body is not always reliable β confirm against the datasheet for flow-under-seat vs flow-over-seat designs. Wrong flow direction can double required actuator thrust and cause chronic instability.
2.3 Body Patterns
T-Pattern
Best throttling. Highest pressure drop. The classic globe valve geometry. Use where flow regulation is the primary requirement.
Angle Pattern
Replaces an elbow. Useful where piping turns 90Β°. Reduces one fitting and one potential leak point in the system.
Y-Pattern
Reduced pressure drop vs T-pattern. Preferred when throttling and efficiency both matter β offshore, high-pressure steam, where ΞP budget is constrained.
2.4 Disc and Plug Geometry β Control Trim
Quick Opening
Most flow occurs in the first 25% of travel. Used for on/off and emergency relief duty where fast response matters more than precise modulation.
Linear
Flow proportional to stem position. Used where system pressure drop is largely constant β easier to control in stable ΞP systems.
Equal Percentage
Equal increments of travel produce equal percentage changes in flow. The dominant trim for control valves on variable-ΞP systems β used in most refinery and process control loops.
2.5 Globe Valve Trim β Materials and API Trim System
Globe valves use the same API trim number system as gate valves. The materials page notes: "Globe valves often require higher hardfacing levels due to throttling duty." A Trim 8 gate valve (hardfaced seat only) in throttling service would fail quickly β globe valves in throttling service typically use Trim 5 or Trim 16 (full hardface on both seat and disc) to withstand the continuous flow impingement and wear of partial-open operation.
| Trim # | Nominal | Seat | Disc / Plug | Stem | Globe Valve Service Notes |
|---|---|---|---|---|---|
| 1 | 13Cr | 410 SS | 410 SS | 410 SS | Light throttling, general service |
| 5 | FHF (13Cr) | Stellite hardfaced | Stellite hardfaced | 410 SS | Steam throttling, severe wear β both surfaces hardfaced for throttling duty |
| 8 | 13Cr + HF | Stellite hardfaced | 410 SS | 410 SS | Isolation duty only in globe valves β not adequate for continuous throttling |
| 10 | 316 | 316 SS | 316 SS | 316 SS | Corrosive service, mild throttling |
| 12 | 316 + HF | Stellite hardfaced | 316 SS | 316 SS | Corrosive + throttling service |
| 15 | FHF (304) | Stellite hardfaced | Stellite hardfaced | 304 SS | High-wear throttling in mildly corrosive service |
| 16 | FHF (316) | Stellite hardfaced | Stellite hardfaced | 316 SS | Severe throttling in corrosive / erosive service β the premium throttling trim |
| 13 | Alloy 20 | Alloy 20 | Alloy 20 | Alloy 20 | Acid throttling service |
2.6 Globe Valve Limitations
Tradeoffs
- Higher ΞP than gate valves
- Heavier and bulkier for given size
- Not economical at very large diameters
- Higher thrust required at high pressure β especially at near-closed throttling
What You Get In Return
- Excellent throttling stability
- Predictable Cv across travel
- Stable disc position under variable load
- The control-valve foundation β all ISA control valve theory is built on globe valve geometry
Globes trade efficiency for control and stability.
2.7 Globe Valve Actuation
Globe valves close directly against flow. In common throttling configurations (flow-under-seat / flow-to-open), closing force rises sharply near the seat: flow velocity increases, pressure differential concentrates at the seat, and closing force escalates. This makes globe valves thrust-intensive at high ΞP.
Flow Under the Disc
Lower opening thrust. Stable control. Standard orientation for most globe control valves. Disc is pushed open by flow β actuator works with the process.
Flow Over the Disc
Higher closing thrust. Risk of chatter. Used in specific applications where fail-closed on loss of signal is assisted by flow force pushing disc onto seat.
Manual Handwheel
Small sizes, low ΞP service, infrequent operation.
Electric Actuators
Used for isolation or coarse control. Slower response than pneumatic. Common for remote on/off globe valves.
Pneumatic Diaphragm
Most common for modulating control service. Smooth force delivery, fast response, inherently fail-safe. The control valve standard.
Piston Actuators
High thrust in compact package. Used for high ΞP control and tight-shutoff globe valves. Faster than diaphragm at large sizes.
3. Check Valves
Automatic protection with no second chances. No operator, no control system β only physics.
- API 594 (9th ed. Feb 2022) β Primary standard: wafer, lug, flanged, and butt-weld check valves. Covers swing, dual plate, lift, and tilting disc designs. Includes P-T ratings, face-to-face dimensions, and testing per API 598. Always paired with ASME B16.34 and MSS SP-61.
- API 602 (11th ed. May 2022) β Compact forged steel check valves β€4". Same standard as for forged gate and globe. Governs small-bore high-pressure check valves in socket weld and threaded configurations.
- API 598 (11th ed. 2023) β Testing baseline: shell test and seat leakage. For check valves, seat leakage testing is performed with flow in the reverse direction to verify the valve closes and seals correctly under back-pressure.
- ASME B16.34 β P-T ratings and wall thickness. Always required.
- ASME B16.10 β Face-to-face dimensions for flanged check valves. Dual-plate (wafer) check valves have short face-to-face β verify against spool before ordering.
- BS 1868 (1975) β Legacy standard for steel check valves in BS-preference specifications. Overlaps API 594.
- MSS SP-71 (2018) β Cast iron swing check valves for water and utility service.
- NACE MR0175 / MR0103 β Sour service: body, disc/clapper, hinge pin, spring, and seat materials must all comply with hardness limits. Springs in check valves are particularly vulnerable to SSC in sour environments β material selection requires specific attention.
3.1 What a Check Valve Actually Does
A check valve allows flow in one direction and closes automatically when flow reverses or decelerates. It protects pumps from backspin, compressors from reverse flow, headers from cross-contamination, and tanks from siphoning. No operator, no control system β only the physics of flow, gravity, spring force, and differential pressure.
3.2 The Hidden Complexity of "Simple" Check Valves
Most check valve failures occur because they are oversized β flow velocity is too low, the valve never reaches full open position, the disc flutters continuously against the stop, and fatigue destroys the internals within months. A check valve is not sized to match the pipe diameter β it is sized to match the actual flow regime in that line.
Check valves must be selected based on flow regime, not pipe size. A check valve sized to match the pipe but oversized for the actual flow will fail early due to disc flutter and internal fatigue. The minimum velocity to fully open a swing check valve is typically 2β4 ft/s depending on design β verify with the manufacturer's minimum velocity curve.
3.3 Common Check Valve Types
Swing Check
Gravity-assisted closure β API 594
- Hinged disc swings on flow
- Piggable in straight-through designs
- Prone to slam at flow reversal β no spring assist
Used in: pipelines, low-velocity systems where slam can be managed.
Dual Plate (Double Door)
Spring-assisted wafer β API 594
- Compact wafer design β short face-to-face per API 594
- Spring-assisted, significantly reduced slam vs swing check
- Not piggable β the central post and dual plates block pig passage
Used in: process piping where space is limited and pigging is not required.
Silent / No-Slam Check
Spring closes before reversal
- Spring forces disc closed before full flow reversal occurs
- Minimizes water hammer β valve is already closed before pressure spike
- Higher ΞP than swing or dual plate
Preferred near pumps and in any system where slam-induced water hammer is unacceptable.
Lift / Piston Check
Disc lifts vertically
- Disc lifts vertically off the seat β must be installed in correct orientation
- Sensitive to fouling β small clearances
- Excellent seat tightness in clean service
Used in: steam, clean liquids, vertical-flow applications.
3.4 Check Valve Trim and Materials
Check valves use the API trim number system (governed by API 594 and API 602 for forged designs). The same seat/disc/stem material philosophy applies β trim number calls out disc/clapper material, seat material, and hinge/pivot material. For sour service, springs must also meet NACE hardness limits β spring material is the most frequently overlooked non-compliance item in check valve sour service procurement.
| Trim # | Seat / Disc Material | Hinge / Pivot | Check Valve Service |
|---|---|---|---|
| 1 | 410 SS | 410 SS | General hydrocarbon service |
| 8 | Seat: Stellite hardfaced / Disc: 410 SS | 410 SS | Erosive hydrocarbon β most common check valve trim |
| 10 | 316 SS | 316 SS | Corrosive service check valves |
| 12 | Seat: Stellite hardfaced / Disc: 316 SS | 316 SS | Corrosive + erosive service |
| 9 | Monel | Monel | Marine and HF acid β check valves in seawater headers |
| 13 | Alloy 20 | Alloy 20 | Acid service check valves |
3.5 Orientation and Location Matter
Horizontal vs vertical installation changes check valve behavior significantly. Gravity assists closure in horizontal swing checks and opposes it in vertical upflow configurations. Turbulent flow from elbows directly upstream destabilizes disc operation and causes premature flutter.
3.6 Slam, Water Hammer, and Dynamic Loads
Water hammer is caused when flow reverses rapidly, the check valve slams shut, and kinetic energy converts to a pressure spike. This can crack valve bodies, shear hinge pins, damage pump seals, and overpressure downstream piping sections.
Non-Spring (Swing)
- Depend on gravity and back-pressure for closure
- Slower closure β reversal begins before valve is fully closed
- More prone to slam at power failure or pump trip
Spring-Assisted (Silent / Dual Plate)
- Spring preload closes valve before full flow reversal occurs
- Dramatically reduced slam and water hammer
- Higher pressure drop accepted as a trade for system protection
3.7 The Biggest Check Valve Mistake
Oversizing "to reduce pressure drop." This causes unstable operation, disc flutter, accelerated wear, hinge pin fatigue failure, and often catastrophic internal destruction. A slightly higher ΞP with stable operation is always better than a low-ΞP unstable valve that fails in months. Always obtain and verify the manufacturer's minimum velocity curve before selecting.
End Connections, Gaskets & Valve Markings
End connection selection determines installation method, leak risk, gasket type, and serviceability. Markings determine traceability. Both are specified on the datasheet and governed by distinct standards from the valve construction standard itself.
| End Connection | Standard | Gate / Globe / Check Application |
|---|---|---|
| Raised Face (RF) | ASME B16.5 / B16.47 | Default for Class 150β600 flanged valves β the most common process piping configuration |
| Flat Face (FF) | ASME B16.5 | Low-pressure utilities where cast iron mating flanges require full-face gasket to avoid bending stress |
| Ring Type Joint (RTJ) | ASME B16.5 / B16.20 | Class 900 and above β refinery and pipeline gate and globe valves in high-pressure, high-temperature service |
| Butt Weld (BW) | ASME B16.25 | Permanent high-integrity installations β eliminates flange leak paths. Common for pipeline gate valves |
| Socket Weld (SW) | ASME B16.11 | Small bore (β€2") forged gate and globe valves β API 602 service |
| Threaded (NPT) | ASME B1.20.1 | Non-critical small bore β utility and instrument service only |
Actuation & Torque β Cross-Valve Comparison
Gate and globe valves are thrust-driven. Check valves are flow-driven and not externally actuated. Understanding the force physics prevents actuator under-sizing β the single most common automated valve failure mode.
| Valve Type | Primary Force | Actuation Method | Control Capability | Typical Challenge |
|---|---|---|---|---|
| Gate | Linear thrust | Manual / electric / hydraulic | Poor β isolation only | High thrust, thermal binding, very large actuators |
| Globe | Linear thrust | Manual / pneumatic / electric | Excellent β throttling and control | High ΞP near closed, actuator stability in modulation |
| Check | Flow-induced (hydrodynamic) | None β not externally actuated | None β automatic only | Slam, flutter, oversizing, spring fatigue in sour service |
| Valve Type | Electric Actuation | Pneumatic Actuation | Hydraulic Actuation |
|---|---|---|---|
| Gate | Common β high thrust, MOV integration. Size for thermal binding. Watch for SSC in sour service if NACE applies to actuator components. | Limited β pneumatic struggles to deliver sustained thrust at gate valve scale. Not preferred. | Critical service preferred β pipelines, ESD, large diameters. Compact for the force delivered. |
| Globe | Limited β slower response, used for remote isolation duty. Not preferred for modulating control. | Standard β diaphragm and piston dominate control service. Smooth modulation, fast response, inherently fail-safe with spring return. | Severe service β high ΞP and emergency shutoff where very high thrust is required in compact space. |
| Check | Not externally actuated. Selection is by valve type (swing / dual plate / silent / lift) and spring vs gravity assist, sized for actual flow velocity in the line β not pipe size. | ||
- Gate valves β electric or hydraulic. Never undersize thrust. Size for maximum ΞP + thermal binding + aged seat friction.
- Globe valves β pneumatic unless proven otherwise. Verify flow direction before installation.
- Check valves β size for stable flow velocity at actual operating conditions, not low ΞP at rated pipe size.
- If the actuator fails, the valve fails. Treat gate and globe valves and their actuators as one integrated system, not separate procurements.
For full actuation coverage including pneumatic / electric / hydraulic / electro-hydraulic architectures and the actuator selection decision tree, see the Valve Actuation reference β
Complete Specification Checklist
Every line item on a valve datasheet must map to a specific standard. If it doesn't, the vendor fills in the cheapest interpretation by default.
- Body material β sets the pressure-temperature envelope (ASME B16.34) and corrosion baseline (ASTM material + NACE if sour)
- Trim (API trim number) β sets shutoff class, wear life, and throttling durability for gate, globe, and check valves
- Bolting β the weakest link if mismatched to body material, service temperature, and sour service requirement
- End connection & facing β determines installation method, gasket selection, leak risk, and serviceability
| Specification Item | Governing Standard | Common Miss |
|---|---|---|
| Gate valve construction | API 600 (large cast) / API 602 (forged β€4") / API 603 (stainless) | Calling only API 600 for a stainless gate valve β should be API 603 |
| Globe valve construction | API 602 (forged) | No specific API for cast globe valves >4" β must specify ASME B16.34 + API 598 directly |
| Check valve construction | API 594 (general) / API 602 (forged β€4") | Specifying only valve type (swing/dual plate) without the governing standard and API 598 test requirement |
| Pressure-temperature rating | ASME B16.34 P-T tables by material group | Using class number as max pressure at all temperatures β misses thermal derating |
| Face-to-face / end-to-end | ASME B16.10 | Not called out β vendor supplies non-standard lay length that doesn't fit the spool |
| Flange dimensions | ASME B16.5 (β€NPS 24) / B16.47 (>NPS 24) | Calling B16.5 for large-diameter gate valves that fall under B16.47 |
| Gaskets | ASME B16.20 (metallic / spiral wound / RTJ) / B16.21 (soft) | Wrong spiral wound ID/OD for the flange bore; wrong RTJ ring number for the class |
| Pressure testing | API 598 + MSS SP-61 | Calling only one β both may be required by the client specification |
| Marking and traceability | MSS SP-25 | Heat number not matched to CMTR β discovered at incoming inspection after delivery |
| Body material | ASTM (A216, A351, A352, A182, A890, etc.) | WCB specified for cold service (needs LCC/LF2); A105 for low-temp (needs A350 LF2) |
| API trim number | API 600 / 602 / 594 trim table | Trim 8 specified for continuous throttling globe valve β needs Trim 5 or 16 (FHF) for throttling duty |
| Body bolting | ASTM A193 / A194 / A320 / A453 | B7 in sour service (needs B7M/2HM); no low-temp rating on B7 (needs L7/7) |
| Fire test | API 6FA (gate / globe / check β all types) | Specifying API 607 for a gate or globe valve β API 607 is quarter-turn soft-seated only |
| Sour service | NACE MR0175 (upstream) / MR0103 (refinery) | Conflating the two standards; check valve spring material not NACE-reviewed |
| Fugitive emissions | API 624 / ISO 15848 (packing) / MSS SP-117 (bellows seal) | Not specified when environmental regulation requires VOC compliance |
Practical Engineering Summary
Gate Valves
Isolate with minimal restriction. Stay-open or stay-closed service. Avoid throttling at all costs. Governed by API 600 / 602 / 603 + API 598 + ASME B16.34. Trim via API trim number β Trim 8 for general hydrocarbon.
Globe Valves
Regulate by controlled pressure loss. The control-valve foundation. Verify flow direction before sizing. Governed by API 602 + API 598 + ASME B16.34. Use Trim 5 or 16 (FHF) for continuous throttling duty.
Check Valves
Protect automatically and unforgivingly. Size for flow regime, not pipe size. Stability over low ΞP. Governed by API 594 + API 598 + ASME B16.34. Trim via API trim number β spring material must meet NACE in sour service.
- API 600 / 602 / 603 / 594 β valve type, construction, performance requirement
- API 598 β testing baseline (shell test + seat leakage) β always required alongside the valve standard
- ASME B16.34 β pressure-temperature ratings β always required
- ASME B16.10 β face-to-face dimensions for interchangeability
- ASME B16.5 / B16.47 β flange interface dimensions and P-T ratings
- ASTM material standards β body, trim, and bolting chemistry and mechanical properties
- MSS SP-25 / SP-61 β marking, traceability, and testing method details
- API 6FA β fire safety for gate, globe, and check (not API 607)
- NACE MR0175 / MR0103 β sour service restrictions when applicable
Specifying a Gate, Globe, or Check Valve?
Send the service conditions (media, pressure, temperature, ΞP), line size, valve role (isolation, regulation, or protection), API trim requirement, and required fail position β we'll come back with a sized recommendation including trim, bolting, end connection, and actuator style.
Knowledge Check
30 questions covering gate, globe, and check valve engineering, governing standards, body materials, API trim numbers, hardfacing, bolting, actuation, fire testing, sour service, and specification pitfalls.
Standard Gate / Globe / Check Valve Procurement
For standard gate, globe, and check valves plus accessories, E4 Industrial supports procurement through our e-commerce arm at Watermain Supply.
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