Flange end ball valves, 1/2" to 6", ANSI · JIS · PN

A flange end ball valve does the same job as a threaded ball valve — a quarter‑turn shut‑off with a drilled ball — but it bolts into the line through a pair of flanges rather than screwing in. That buys you three things: it goes to larger sizes than a threaded body sensibly can, it comes out of the line without cutting or unscrewing pipework, and it is the normal arrangement on plant where valves are expected to be removed for service.

It also introduces the one constraint that governs everything on this page. The flange has to match the flange it bolts to — the same bolt circle, the same number of holes, the same hole diameter, the same raised face. That is set by the flange standard, and the four here are not interchangeable. An ANSI 150 valve will not bolt to a JIS 10K flange, and neither will bolt to a PN16 one.

• ⚠ Get the flange standard from the pipework, not from the pressure. ANSI 150 and JIS 10K are close in pressure — both around 1.6 to 2 MPa — but their bolt circles differ, so they do not mate. Measure or check the existing flange before ordering. All four standards side by side.
• Every variant is built to a different design standard. API 608, ANSI B16.34, API 6D, JIS B2071 and EN 1983 all appear across the six. If your specification names one of those, it names the variant. The full stack.
• ⚠ The cast steel variants are not stainless valves. The body is A216 WCB cast carbon steel and the ball and stem are 304, not 316. Corrosion resistance is well below the SS316 variants. The difference.
• Each variant publishes its own test pressures — shell, seat and gas‑tightness — and they scale with class: 3.0 MPa shell at Class 150 against 7.8 MPa at Class 300. The figures.
• Threaded instead? For 1/8" to 4" screwed or weld‑end valves, see ball valves — eight variants including three‑way L and T‑port.

On a flanged valve the standards are not paperwork — they are the dimensions. The design standard sets the construction and testing, the face‑to‑face standard sets the length between flange faces so the valve fits the gap in the pipe run, and the flange standard sets the drilling. All three have to be right.

• API 608 is the ball valve standard for flanged and threaded metal valves, and it is what both cast‑steel variants are built to. If a specification says “ball valve to API 608”, those are the two.
• API 6D is the pipeline valve standard — a heavier, pipeline‑oriented specification than API 608. Only the ANSI 300 SS316 is built to it, and it is the one to quote on pipeline work.
• ANSI B16.34 appears in two roles. It is the design standard for the ANSI 150 SS316 valve, and the wall thickness standard for both cast‑steel valves. Same document, different scope — worth knowing if a specification cites it without saying which.
• ⚠ The ANSI 150 SS316 valve carries GB flange and face‑to‑face standards — GB/T 9113.1 and GB/T 12221 — not ASME ones. GB/T 9113.1 flanges are dimensionally aligned with ANSI 150, but if your specification insists on ASME B16.5 flanges specifically, tell us and we will confirm before quoting.
• Face‑to‑face is the dimension that decides whether it drops in. It is column L on every variant page. Measure the gap in the run before ordering, especially on a replacement.

Of the six, four are SS316 and two are cast carbon steel. The cast‑steel pair is materially different in a way the name does not make obvious, so it is worth setting out part by part.

• ⚠ Cast steel means carbon steel with 304 trim. Body in A216 WCB, ball and stem in 304. It is a perfectly good valve for water, air, oil and general non‑corrosive service — and it is not a substitute for SS316 where corrosion is the reason stainless was specified.
• Graphite packing is the cast‑steel advantage. Flexible graphite packing and a graphite‑faced gasket take more heat than PTFE and behave better under thermal cycling. On hot, clean, non‑corrosive duty that is a real point in its favour.
• Only the cast‑steel variants list an anti‑static device. A ball turning on PTFE seats is electrically isolated; the SS304 anti‑static device bonds it back to the body. It matters on hydrocarbons. The SS316 parts lists here do not include one — ask us if you need it.
• The bolting is stronger on cast steel too. A193 B7 studs with A194 2H nuts are alloy‑steel pressure bolting; the SS316 variants use SS304 fasteners, which are more corrosion‑resistant but lower strength.
• PTFE seats throughout. Both families seal on PTFE, which is why every variant tops out around 150 °C regardless of what the body is made of.

Ball valves: threaded and weld end, 1/8" to 4" · high pressure ball valves · SAE flange end ball valves · ISO 6164 ball valves. Other flanged valves: gate valves · globe valves where throttling rather than isolation is wanted · butterfly valves · swing check valves · Y‑strainers to keep grit off the seat. And all low pressure valves.