Ball valves, 1/8" to 4", in SS316 and brass

A ball valve is a shut‑off valve that controls the flow of a liquid or gas. Ball valves split into low pressure and high pressure types, and different industries use different ones depending on their working pressure requirement. The low‑pressure range is widely used for water, general oil and gas applications — and also for critical applications with demanding requirements, so “low pressure” describes the class, not the importance of the duty.

Two questions settle it. Will the valve ever be opened for service? Never → one‑piece. Possibly → two‑piece. Yes, and the line cannot be shut down to do it → three‑piece. Then: does flow area matter? If yes you need full bore, which rules out the one‑piece. Diverting or mixing instead of isolating? L‑port or T‑port. All eight side by side.

The number of pieces the body is made from, which decides whether it can be serviced. The one‑piece has body and ends made from a single piece of material — a solid cast body that significantly decreases the risk of leakage, but it cannot be taken apart. The two‑piece is the most commonly used: it allows disassembly to replace internal parts, at the cost of a potential leak path where the two pieces join. The three‑piece is two end caps and a body, which separates the pipe connections from the rest of the valve so it prevents a line shutdown if maintenance is required. Longer answer.

A full bore valve has an over‑sized ball, making the hole in the ball the same size as the pipeline — it does not restrict flow. A reduced bore valve has a flow area less than the inner diameter of the pipeline, and is generally used in switches and circuits for general hydraulic applications. The gap is bigger than it sounds: at 1/2" the bores are 9 mm and 15 mm, so the reduced‑bore valve passes roughly 36% of the area. Every size.

No — it follows the construction. A one‑piece ball valve is always reduced bore, because the trim is inserted through one of the end connections, so the port size cannot equal the line size. The two‑piece is the standard (full) bore, and the three‑piece is full bore too. Both three‑way variants and both minis are reduced. If you need full bore, you are choosing between the two‑piece and the three‑piece.

1/8" to 4" (DN6 to DN100) across the range, but not every variant covers all of it. 1/8" comes only from the SS316 mini; the brass mini stops at 3/4"; the three‑way pair stops at 2"; and the one, two, three‑piece and brass all run 1/4" to 4". The table.

It depends on the variant and it is not a small spread. Brass is 300 PSI. The stainless variants are 1000 PSI. The two‑piece is also supplied in a separate 2000 PSI range with its own dimensions and part numbers — it is the only variant that goes that high. All of those are cold figures; temperature takes some back.

Only if the duty fits 300 PSI, which is roughly a third of the stainless rating — so it is not a like‑for‑like substitution. Brass is a sound choice for water, air and non‑corrosive service at modest pressure. Against corrosion, SS316 is the standard material because of its high corrosion resistance. Also note the brass valve is not all brass: the handle is aluminium, the nut is steel and the O‑ring is NBR. the full brass ball valve parts list.

−29 °C to 150 °C, and the environment temperature affects the working pressure inside that band. The manufacturer’s curve is flat at 63 bar up to about 20 °C, then falls in a straight line to 42 bar at 150 °C — about 67% of the cold rating — and stops dead there. The limit is the PTFE seat, not the stainless body. The full table.

How the ball is drilled, and therefore what the handle positions do. An L‑port connects two ports at a time — it diverts flow from one outlet to the other, or shuts off. A T‑port can connect all three at once, so it will mix, split or divert. Mechanically they are the same valve: identical bodies, identical face‑to‑face dimensions, identical weights. You can swap one for the other without touching the pipework. L‑port · T‑port.

Yes — socket weld and butt weld ends on the three‑piece, which is the only variant in this range offered welded at all, alongside BSPP and NPT. That pairs naturally with the three‑piece design: welded end caps stay in the pipe and the centre section still comes out for service.

Yes, but not from this page. Everything here is threaded or socket weld, in SS316 and brass. For flanged bodies and for cast and forged carbon steel, go to flange end ball valves — ANSI 150 and ANSI 300, in cast steel, forged steel and SS316. For higher classes, high pressure ball valves.

Clean the pipes of all objects, align both sides, check the sections match because the valve cannot absorb any gaps, support unsupported pipework so there is no strain on the valve, apply thread sealant, then double‑check tightness. Four of the six steps are about the pipe, not the valve — because any distortion in the pipes can affect the tightness of the connection, the functioning of the valve, and can even result in a rupture. The sequence.

On the stainless variants: SS316 and CF8M body and cap, SS316 ball and stem, PTFE seat, seal gasket, stem seal and stem packing, with an SS304 anti‑static device, SS304 packing gland, SS301 spring washer and an SS201 handle. On brass: brass body, bonnet and stem, chrome‑plated brass ball, PTFE seat, NBR O‑ring, aluminium handle, steel nut. Every variant page publishes its own full list.

Close to it in normal service — the quarter‑turn design requires almost no maintenance. What wears is the PTFE seat, usually from grit carried down the line, which is exactly why step one of installation is to clean the pipes. When the seat does go, the construction decides your options: the two‑piece and three‑piece can be stripped and re‑seated, and the one‑piece is replaced.

Every valve in this range is supplied lever operated, and the manufacturer does not publish an ISO 5211 mounting pad for any of the eight — no pad size, no bolt pattern, no stem square. So we cannot tell you from the datasheet whether a standard actuator will bolt on. Tell us the size and the actuator you have in mind and we will get the mounting details from the factory before you order. If you need a valve that is designed from the start to be actuated, we stock one: the PN16/PN40 SS316 wafer type ball valve carries F03 and F04 cast into its top plate and a dedicated ISO 5211 pad detail on the manufacturer’s section. It is a flanged‑pipework valve, not a threaded one, so it is a different fitting job — but it is the one ball valve here whose actuator interface is actually published. What it still does not publish is torque, and an actuator has to be sized on torque, so we would chase that figure either way. Note that our butterfly valves do publish a top‑flange drilling — 4‑7 mm on a 50 mm circle up to 3", 4‑9 on 70 mm from 4" up.

Not as a published option. The parts lists for these eight valves show a plain aluminium or stainless lever with a nut — no locking device, no padlock hasp, no memory stop. If your site procedure needs a valve that can be padlocked shut, tell us at enquiry stage: it is a question for the factory rather than something we can answer from the catalogue, and it is much easier to specify than to retrofit. Do not assume a lever can be locked just because it has a hole in it.

Ask, and we will obtain them. Certification is not published in the catalogue for this range, so we do not claim it on the page — but the castings do carry heat numbers, which is what makes traceability possible in the first place. If your order needs EN 10204 3.1 material certificates, say so with the enquiry rather than after delivery: certificates have to be issued against the specific heat the valves came from, and that is far harder once stock has been picked and shipped.

Four things buyers ask for that the manufacturer does not print, and we would rather list them than have you assume. There is no Cv or flow coefficient, so pressure drop cannot be calculated from the datasheet — though a full bore valve is close to the pipe itself, and reduced bore costs you more than people expect. There is no ISO 5211 actuator pad on any of the eight — the only ball valve we stock that publishes one is the PN16/PN40 wafer type, and that is a flanged‑pipework valve. There is no API 608 or fire‑safe certification — these are soft‑seated PTFE valves and nothing in the literature claims a fire‑safe design, so if your specification calls for one, this range does not meet it on paper. And there is no published certification package. We will chase any of these with the factory; what we will not do is print a figure we have not been given.