How to Write a Valve Datasheet: Complete Specification Guide for Engineers

Section 1: Service and Process Data

The process data section tells the manufacturer what environment the valve must survive. It must include: Service fluid (e.g., 'Crude oil with H2S', not just 'oil'); Fluid phase (liquid, gas, vapour, two-phase); Normal operating pressure and temperature; Design pressure (MAWP — maximum allowable working pressure); Design temperature (minimum and maximum); Specific gravity or density at operating conditions (for Cv sizing); Viscosity if above 1 cSt (affects Cv formula); Hazard classification — flammable, toxic, oxygen service (special cleaning required for oxygen).

Section 2: Valve Identification and Type

Tag number (unique identifier matching P&ID), service description, quantity, valve type (ball, gate, globe, butterfly, check, plug, needle, safety relief), and body pattern (full bore/reduced bore for ball valves; wedge type for gate valves; T-pattern/Y-pattern/angle for globe valves).

Section 3: Size and Pressure Class

Nominal pipe size (NPS in inches or DN in millimetres), ASME pressure class or PN rating, end connections (RF flanged ASME B16.5, RTJ, BW, SW, threaded NPT/BSP), face-to-face dimension standard (ASME B16.10 is standard for most valve types), and bore specification (full bore or reduced bore for ball valves).

Section 4: Materials

Section 5: Shutoff and Testing

Leakage class per ANSI/FCI 70-2: Class IV is standard for metal-seated isolation valves; Class VI for soft-seated and gas service where bubble-tight shutoff is required. Testing standard: API 598 or ISO 5208 — specify which and the required leakage rate. Whether TPI (third-party inspection) is required and which agency. Whether PMI (Positive Material Identification) is required on all CRA components.

Section 6: Actuator (if automated)

• Actuator type: pneumatic spring-return (specify spring-to-open or spring-to-close = fail direction), pneumatic double-acting, electric
• Fail-safe direction: FC (fail-closed), FO (fail-open), FL (fail-last)
• Supply pressure: minimum, normal, and maximum instrument air pressure
• Control signal: on-off (solenoid), or modulating (4–20 mA with positioner)
• Accessories: solenoid valve (AC or DC, ATEX if hazardous area), limit switches (SPDT or DPDT, ATEX), positioner type, handwheel override
• Hazardous area classification: ATEX Zone 1/Zone 2, IECEx, NEC Class I Division 1/2

Section 7: Special Requirements

NACE MR0175 compliance (if H2S present); fire-safe certification (API 607 or ISO 10497); cryogenic testing (extended bonnet, low-temperature impact test); fugitive emissions (ISO 15848 Class A); anti-static device (conductive path stem-to-body — required on all ball valves in API 6D); locking device (lockable in open or closed position for safety critical isolation); paint specification (epoxy primer + topcoat, colour code, film thickness).