API 598 Valve Inspection and Testing

Valve Inspection and Testing

1 Scope

1.1 This standard covers inspection, examination, supplementary examinations, and pressure test requirements for resilient-seated, nonmetallic-seated (e.g. ceramic), and metal-to-metal-seated valves of the gate, globe, plug, ball, check, and butterfly types. Resilient seats are considered to be:

1. a)  soft seats, both solid and semisolid grease type (e.g. lubricated plug);

2. b)  combination soft and metal seats (e.g. laminated seat rings);

3. c)  any other type of seat material designed to meet resilient seat leakage rates as specified in Table 5.

API Standard 598 supplements the API standards that reference it, but it may also be applied to other types of valves by agreement between the purchaser and the valve manufacturer. Reference Annex A for information to be specified by the purchaser.

1.2 The inspection requirements pertain to examinations and testing by the valve manufacturer and any supplementary examinations that the purchaser may require at the valve manufacturer’s plant. The test requirements cover both required and optional pressure tests at the valve manufacturer’s plant or at a facility mutually agreeable to both the manufacturer and the purchaser.

1.3 The following tests and examinations are specified in this standard:

1. a)  shelltest,

2. b)  backseattest,

3. c)  low-pressure closure test,

4. d)  high-pressure closure test,

5. e)  double block and bleed high-pressure closure test,

6. f)  visual examination of castings,

7. g)  high-pressure pneumatic shell test.

2 Normative References

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

ASME B16.11,1 Forged Fittings, Socket-Welding and Threaded

ASME B16.34, Valves—Flanged, Threaded, and Welding End

MSS SP-45,2 Bypass and Drain Connections

MSS SP-55, Quality Standard for Steel Castings for Valves, Flanges and Fittings and Other Piping Components Visual Method for Evaluation of Surface Irregularities