API 598 pdf download.Valve Inspection and Testing
1.1 SCOPE 1.1.1 This standard covers inspection, examination, supple- mentary 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: a. Soft seats, both solid and semi-solid grease type (e.g., lubricated plug). b. Combination soft and metal seats. c. Any other type valve designed to meet resilient seat leak- age rates as specified in Table 5. API Std 598 supplements the API standards that reference it, but it may also be applied to other types of valves by agree- ment between the purchaser and the valve manufacturer. 1.1.2 The inspection requirements pertain to examinations and testing by the 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 manufac- turer’s plant. 1.1.3 The following tests and examinations are specified in this standard: a. Shell test. b. Backseat test. c. Low-pressure closure test. d. High-pressure closure test. e. Visual examination of castings. f. High-pressure pneumatic shell test.
2 Inspection, Examination, and Supplementary Examination
2.1 INSPECTION AT THE VALVE MANUFACTURER’S PLANT The purchaser will specify in the purchase order his inten- tion to inspect valves and witness tests and examinations at the valve manufacturer’s plant. The purchaser’s inspector shall have free access to any part of the plant concerned with manu- facture of the valves whenever work on the order is under way. 2.2 INSPECTION OUTSIDE THE VALVE MANUFACTURER’S PLANT When the purchaser specifies that the inspection will include shell components manufactured at locations other than the valve manufacturer’s plant, these components shall be subject to the purchaser’s inspection at the location where they are manufactured. 2.3 INSPECTION NOTICE When inspection by the purchaser is specified, the valve manufacturer shall notify the purchaser 5 working days prior to the required valve testing and any specified supplementary inspections or examinations, addressing the notice as stated in the purchase order. The valve manufacturer shall also give the purchaser 5 working days’ notice of where and when shell components manufactured outside the valve manufacturer’s plant may be inspected, if such inspection is required.2.4 EXTENT OF INSPECTION The extent of inspection may be specified in the purchase order and, unless otherwise indicated, will be limited to the following: a. Inspection of the valve during assembly to ensure compli- ance with the specifications of the purchase order. Inspection may include the use of specified nondestructive methods. b. Witnessing of the required and specified optional pressure tests and examinations. c. Witnessing of any supplementary examinations (see 2.6). d. Review of mill records and nondestructive examination records (including specified radiographs). 2.5 EXAMINATION 2.5.1 A visual examination shall be performed by the valve manufacturer of all castings of bodies, bonnets, covers, and closure elements to assure conformance with MSS SP-55. 2.5.2 The valve manufacturer shall examine each valve to assure compliance with this standard and the referenced pur- chase specification (e.g., API Std 599). 2.5.3 All examinations shall be performed in accordance with written procedures that comply with the applicable stan- dards. 2.6 SUPPLEMENTARY EXAMINATION Supplementary types of examination are required only if specified in the purchase order and only to the extent speci- fied. Magnetic particle, radiographic, liquid penetrant, and ultrasonic examination of steel castings or forgings shall be in accordance with Part 8 of ASME B16.34 or with the pur- chaser’s own procedures and acceptance criteria, if so speci-fied. These examinations shall be made by the valve manufacturer subject to witnessing by the purchaser’s inspector.