Industrial valves are the control organs of any process line. They start, stop, isolate, regulate and protect the flow of oil, gas, steam, water and chemicals through refineries, power plants, petrochemical complexes, LNG terminals, desalination units and ship engine rooms. A typical oil and gas project carries several thousand valves across dozens of service classes, and almost every one of them has to be specified, certified, shipped and tested alongside matching pipe, fittings and flanges. The procurement team that treats the valve as a stand-alone buy usually pays for that decision later — in mismatched pressure-temperature ratings, in late deliveries, and in field rework. The procurement team that bundles the valve package with the piping package, on the other hand, saves time, money and certification effort. This guide explains how to build that bundled package correctly.

Step 1 — Classify Every Valve by Function, Not by Nameplate

Before any RFQ goes out, every valve position on the line list must be classified by what it is supposed to do, because the function drives the type, the type drives the body, and the body drives the cost. The four functional families cover the vast majority of industrial service.

• Isolation — fully open or fully closed. Gate, ball, plug and butterfly valves dominate here.
• Regulation / throttling — partial opening to set flow or pressure. Globe, control and angle valves are the working choice.
• Check (non-return) — prevents reverse flow automatically. Swing check, lift check, dual-plate and nozzle check valves.
• Safety / relief — protects equipment from over-pressure or over-temperature. Safety valves, relief valves, rupture discs and steam traps.

Step 2 — Match The Valve Type To The Service

Within each functional family, a handful of standard types cover almost every industrial case. The table below summarises where each type fits and where it should be avoided.

For most oil, gas and power plant lines, the project will end up with a mix: gate or ball valves for mainline isolation, globe or control valves on regulation loops, check valves on every pump and compressor discharge, and safety / relief valves on every fired vessel and steam drum. Specifying the same set across a project keeps spares, actuators and training consistent.

Step 3 — Choose The Right Body Material

The valve body must be metallurgically compatible with the pipe, the fluid and the operating temperature. Three families cover the great majority of industrial service.

Carbon and carbon-alloy steel

ASTM A216 WCB and A352 LCC are the workhorses for hydrocarbon and steam service up to about 425 °C. For low-temperature service (down to −46 °C) A352 LCC and A350 LF2 are standard. For sour service (NACE MR0175), specify HIC-resistant or low-hardness variants. Carbon-steel valve bodies are the most economical choice for the bulk of the line and are normally paired with carbon steel pipe of the same standard family.

Stainless steel

A351 CF8 / CF8M (304 / 316 equivalents) are used for food, pharmaceutical, water, mildly corrosive chemical and clean service. For higher temperature and creep resistance, austenitic 321H, 347H or duplex 2205 are preferred. When the line is built around stainless steel pipe for corrosion reasons, the valve body should match the same UNS number to avoid galvanic mismatch at the joint.

Alloy and copper-nickel

For seawater, firewater, ship cooling and desalination service, copper-nickel bodies (B466 / B467 grades) match the system metallurgically and provide excellent resistance to chloride pitting and biofouling. For high-temperature and corrosive chemical service, alloy bodies (Monel, Inconel, Hastelloy) are specified against the corrosion diagram. These alloys pair with the copper nickel alloy pipe family on the same service line.

Step 4 — Lock The Standard And The Pressure Class

Valve pressure class is not a free-standing number. It is the combination of body material and design temperature that the standard allows. An ASME Class 600 carbon-steel valve at 50 °C has a different allowable pressure than the same valve at 400 °C, and the standard is explicit about it.

The four standard systems cover the great majority of industrial projects:

• ASME B16.34 — the international default for oil, gas and power; classes 150 to 2500.
• API 600 / API 6D — required by most operators for gate and ball valves on hydrocarbon pipeline service.
• EN 12516 / EN 1349 — the European pressure-temperature system; PN classes 10 to 420.
• GB / JB / HG — the Chinese national system for domestic projects.

For any project, the cleanest approach is to pick one standard family and stick to it across the valve, the pipe, the fittings and the pipe flanges. Mixing ASME valves with EN flanges in the same line is a frequent dimensional mismatch that surfaces only at site.

Step 5 — Don't Forget The End Connections And Actuators

A valve does not live alone. The end connection — flanged, butt-weld, socket-weld, threaded or wafer — must match the rest of the line. For high-pressure and critical service, butt-weld ends are preferred for leak-tightness. For maintenance-friendly service, flanged ends allow removal without cutting the pipe. For large butterfly valves, wafer and lug bodies sandwich between the existing flanges and save both space and weight.

Actuation is the second decision. Manual gear operators are sufficient for infrequently operated valves; electric, pneumatic or hydraulic actuators are needed for remote operation, control loops or ESD (emergency shut-down) duty. For ESD duty, specify fire-safe bodies, anti-static devices, and SIL-rated actuators per IEC 61511.

Step 6 — Bundle The Valve Package With The Rest Of The Piping

The fastest way to lose control of a project valve package is to buy valves from one supplier, pipe from another, fittings from a third, and flanges from a fourth. Every interface between suppliers is an opportunity for material mismatch, document delay and late delivery. The bundled approach — buying the whole piping package from one mill with full traceability — is a well-established best practice on oil, gas and power projects for three reasons:

• Material consistency. One heat-number trail runs through the pipe, the fittings, the flanges and the valve bodies, simplifying MOC files and PMI checks at site.
• Single certificate package. EN 10204 3.1 / 3.2 mill test certificates, NDT reports and pressure-test records come from one source, in one format, in one delivery window.
• Single point of accountability. One shipping window, one customs clearance, one contact for any field issue — and no blame between suppliers when something has to be reworked.

For projects with aggressive schedules, the bundled approach can shave weeks off the procurement cycle. It also allows the mill to optimise the production schedule, which translates into better pricing on the bulk items such as pipeline works line pipe and matching fittings.

A Practical Valve Procurement Checklist

Before issuing the valve RFQ, walk through this list once:

1. Service fluid, design pressure, design temperature, and any cycling / vibration load — confirmed in writing on the datasheet.
2. Functional duty per valve — isolation, regulation, check, or safety / relief. One type per position.
3. Body material — carbon steel (WCB / LCC) for hydrocarbons; stainless (CF8 / CF8M) for clean service; alloy or copper-nickel for corrosive service. Match the pipe material on the same line.
4. Standard and pressure class — ASME B16.34, API 600 / 6D, EN 12516 or GB. One family for the whole project.
5. End connections — flanged, butt-weld, socket-weld, threaded or wafer. Match the rest of the line.
6. Actuation — manual, gear, electric, pneumatic, hydraulic. SIL rating for ESD duty.
7. Inspection and testing — hydrotest, NDT, PMI, fire-safe certification, low-emission packing. Document scope in the RFQ.
8. Bundling — confirm the supplier can deliver matching pipe, fittings, flanges, gaskets and stud bolts on the same shipping window with one certificate package.