API 602 Forged Steel Valves
API 602 forged steel check valves prevent backflow on small-bore high-pressure lines. Lift (piston) and ball types give good sealing on lines with vibration and pulsation; swing types are preferred where low pressure drop is required.
Overview
They are supplied with a bolted or welded bonnet; ends are NPT, socket-weld, butt-weld or flanged. Lift types are generally installed in horizontal lines, while spring-loaded designs can be used in other orientations. For how lift, ball and swing designs compare, see check valve types explained.
Technical specifications
| Size | ½”–2″ (DN15–DN50) |
|---|---|
| Pressure class | Class 800 and 1500 (API 602); Class 2500 to ASME B16.34 |
| Type | Lift (piston), ball, swing |
| End connections | NPT, SW, BW, flanged |
| Materials | A105N, LF2, F11, F22, F316 |
Key features
- Compact forged body for high pressure
- Good sealing on vibrating lines
- Spring-loaded design options
Standards and construction
- Design: API 602 / ISO 15761, ASME B16.34
- End connections: socket weld (ASME B16.11), threaded NPT (ASME B1.20.1), butt weld (ASME B16.25), flanged (ASME B16.5)
- Bonnet types: bolted or welded cover (pressure seal in high classes, to ASME B16.34); piston, ball and swing internals
- Port: standard (reduced) or full port
- Testing: API 598
Material combinations
| Combination | Body / bonnet | Trim | Typical service |
|---|---|---|---|
| A105 / F6a | A105 | 13Cr (F6a) | General hydrocarbon, water, air, steam |
| A105 / F6a + hardfacing | A105 | 13Cr + CoCr hardfaced seat | Steam, high temperature, abrasive service |
| LF2 / 304 | A350 LF2 | 304 | Low temperature (down to approximately −46 °C) |
| F11 / F6a + hardfacing | A182 F11 | 13Cr + CoCr hardfacing | Superheated steam, high temperature |
| F304 / 304 | A182 F304 | 304 | Corrosive service |
| F316 / 316 | A182 F316 | 316 | Corrosive and chemical service |
| F51 / F51 | A182 F51 (duplex) | F51 | Chloride environments; seawater depending on conditions |
Documentation and testing
On industrial projects the documentation package matters as much as the valve. We confirm the certificate and test scope for every line item at quotation stage:
- EN 10204 3.1 material certificates for pressure-retaining and wetted parts, traceable by heat number
- EN 10204 3.2 with third-party inspection, on request
- Pressure test reports to API 598 or EN 12266-1: shell, seat and, where specified, gas tests
- Fire-test certificates (API 607 / ISO 10497) for fire-safe type-tested designs
- PMI reports for alloy and stainless materials
- Dimensional, visual and coating inspection records
- PED 2014/68/EU CE declaration for equipment within its scope
- NACE MR0175 / ISO 15156 compliance statement for sour (H₂S) service
Technical datasheet
Frequently Asked Questions
In which orientation is a lift check valve installed?
Lift (piston) check valves without springs are generally installed in horizontal lines with the bonnet upward. Spring-loaded designs can also be used vertically and in other orientations; the installation orientation should be stated in the order.
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View detailsRequest a quote: API 602 Forged Steel Check Valve
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