Industrial Valve Manufacturer in Taiwan: Ball Valves, Check Valves and Y Strainers From One Plant

SZ Valves is an industrial valve manufacturer in Taichung, Taiwan. One plant casts, machines, assembles and leak tests stainless steel ball valves, check valves and Y strainers, so the isolation, backflow and strainer positions on a line can be quoted from one factory and placed on one purchase order.

If you are filling a line list rather than buying one valve, this is the short route. For the check valve alone, the check valve manufacturer guide goes deeper; for the strainer alone, see how to choose a stainless steel Y strainer.

Key takeaways

• Range from one plant: threaded ball valves 1/4″ to 4″, flanged ball valves 1/2″ to 8″, check valves 1/2″ to 4″, Y strainers 1/4″ to 3″. Bodies are cast CF8 (304) or CF8M (316); carbon steel is quoted to order.
• Ratings to put on the inquiry: 1000 WOG on the threaded and sanitary ball valves, 800 WOG on the Y strainers, 200 PSI (WOG) on the threaded swing check. The flanged valves are specified by flange class. WOG is a cold rating for water, oil and gas, not a steam rating.
• Threads are PT, NPT or PF, and the stock thread differs by series. The flanged check valve has ASME B16.5 Class 150 or JIS B2220 10K flanges. The flanged ball valve is made in ANSI Class 150, Class 300, JIS 10K and JIS 20K.
• Every valve is leak tested and checked for dimensions before it ships. We hold ISO 9001 and CE. A mill test report and a dimensional inspection report are available on request.
• To quote all three positions, we need, per position: size and quantity, body grade, end connection, line conditions, marking and the documents you want.

What an industrial valve manufacturer is, and why it matters on a mixed order

An industrial valve manufacturer makes the valve in its own plant; some, like us, also pour their own castings. Industrial valve suppliers that trade rather than make buy finished valves from several plants and resell them under one invoice. Both can fill a line list. The difference shows up after the order: whose name is on the material certificate, who answers when a dimension does not match the drawing, and whether the ball valve, the check valve and the strainer were made to the same thread standard and the same grade.

When the three positions come from three plants, that alignment is your job. When they come from one plant, the whole list is quoted from one factory, by the people who make the parts. Our guide to checking a valve casting manufacturer before you order lists the questions that separate a foundry from a reseller. The short version: ask where the castings are poured and who signs the certificate.

The three positions on a line, and what we make for each

Many lines repeat three positions: a ball valve to isolate a section, a check valve to stop reverse flow, and a Y strainer to catch debris before it reaches a pump, a meter or a control valve. Some add a three-way valve where flow has to be diverted. The table lists what SZ Valves casts for each position, taken from the product pages.

Check two things in the table. The stock thread is not the same across the range: PT is stock on the three-way valve, the swing check and both strainers, and the three-piece valve carries PT, NPT and PF in stock. For the other series, tell us the thread you need and we will confirm what is on the shelf. The pressure figures also mean different things. 1000 WOG, 800 WOG and 200 PSI (WOG) are cold ratings for water, oil and gas. The flanged valves are specified by flange class; give us the operating pressure and temperature as a pair.

The ball valves have PTFE seats, the strainers have PTFE gaskets and O-rings, and the ball valves run from −20°C to 180°C. Where a line needs automation, the pneumatic actuated ball valve comes with a rack-and-pinion actuator matched, mounted and cycle-tested on the valve, and the SZ-25 electric actuator covers quarter-turn valves from 3/8″ to 1-1/4″ for indoor installations, with battery backup as standard. Our ISO 5211 mounting pad article explains how to order a manual valve today and automate it later.

Five mistakes that show up when the three positions come from three suppliers

The mistakes below all come from the three positions not matching each other.

1. Three suppliers, three thread standards

PT is the tapered thread of the Japanese standard; NPT is the American tapered thread; PF is the Japanese parallel pipe thread. A PT strainer and an NPT nipple are not a matched pair, and the mismatch is usually found at installation. Decide one thread standard for the line. Write it on every position. Then check which thread is stock for each series before you assume it ships from stock.

2. Reading WOG as a steam or temperature rating

1000 WOG means 1000 psi of cold water, oil or gas. It says nothing about steam, and it is not a rating at 180°C. If the line runs hot or carries steam, put the operating pressure and temperature on the inquiry as a pair, and we will tell you which valve suits the point. If your specification calls for ASME B16.34, put that on the inquiry too.

3. Writing “stainless steel” without the grade

CF8 is cast 304 and CF8M is cast 316. The molybdenum in CF8M improves its resistance to pitting in chloride-bearing water compared with CF8, a point the Specialty Steel Industry of North America explains in its corrosion notes. On a mixed order the risk is choosing a different grade at each position without meaning to. Name the grade per position. CF8M is offered on every product in the table, so in CF8M the grade can be held constant across the order.

4. Asking for the material certificate after the goods have shipped

A mill test report for the body material is available on request, and so is a dimensional inspection report. Name them on the inquiry so they are prepared with the order. An email after delivery is the slow way to get them.

5. Ordering the strainer before deciding how it will be cleaned

A blow-off plug is opened with a wrench. The Y strainer with drain valve replaces the plug with a quarter-turn ball valve, so the screen can be blown down by hand. If the line is flushed on a schedule, or the strainer sits where a wrench will not reach, specify the drain valve build. Decide which one you need when you specify the mesh.

How SZ Valves makes all three in one plant

We started as a precision machining shop and set up as a valve maker in 1995. Today the plant in Longjing, Taichung runs precision machining, its own foundry, valve development and actuator assembly on one site, with more than 150 people.

The ball valve bodies are investment cast, and they all go through the same sequence: wax injection, tree assembly, ceramic dipping, shell drying, dewaxing, shell firing, casting and cleaning, then machining. The check valve and strainer bodies are poured in the same foundry. Because the pour and the machining happen on the same floor, the material certificate and the finished valve come from the same plant.

Every valve is leak tested and checked for dimensions before it ships. The threaded swing check is also tested to API 598, the API standard for valve inspection and pressure testing. We hold ISO 9001 and CE. More on the plant is on our About page.

For buyers who need their own identity on the parts, we laser mark or stamp part numbers on the body, apply labels and pack in color boxes to your branding. Builds to your drawing are quoted as a project, with an NDA signed first if you need one. The OEM and custom manufacturing page describes how that works, including a custom programme for a semiconductor wafer fab that has run for ten years.

What to send so all three can be quoted together

One list is enough. For each position on the line, give us:

• Position and type: isolation, backflow or strainer, and the valve type if you have already chosen it (two-piece, three-piece, flanged, swing, spring, plug or drain-valve strainer).
• Size and quantity per position.
• Body grade: CF8 (304) or CF8M (316). Carbon steel can be quoted to order.
• End connection: PT, NPT or PF for threaded items; Class 150, Class 300, JIS 10K or JIS 20K for flanged items; socket weld, butt weld or Tri-Clamp where the design calls for it.
• Line conditions: fluid, operating pressure and temperature. For the strainer, add the mesh or the particle size you need to stop.
• Marking and packing: your part number, brand marking, label or box requirements.
• Documents: mill test report, dimensional inspection report, or anything your QA procedure asks for.
• Your drawing or part reference, if the item has to match an existing installation.

Regular items ship from stock. A thread we do not hold, a grade outside the standard line or a build to your print is made to order and quoted per job. The minimum order quantity is agreed in the quote; it depends on the model and the marking. Payment is T/T, 30% with the order and 70% before shipment, and we ship FOB, CIF or on the Incoterm you normally use.

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FAQ

Can one industrial valve manufacturer quote ball valves, check valves and Y strainers together?

Yes. SZ Valves casts, machines and tests all three in the same plant in Taichung, Taiwan, and the whole list is quoted from one factory. Send the size, quantity, body grade and end connection for each position. Threaded ball valves run 1/4″ to 4″, flanged ball valves to 8″, check valves 1/2″ to 4″ and Y strainers 1/4″ to 3″.

Which stainless grades are standard, and can you quote carbon steel?

CF8 (cast 304) and CF8M (cast 316) are our two standard grades. CF8M is the stock grade on the three-way ball valve, the threaded swing check and both Y strainers. CF8 is made to order on the three-way, pneumatic and strainer bodies; the three-piece and sanitary ball valves and the threaded swing check are listed in CF8M only. Carbon steel bodies can be quoted to order.

Which thread is in stock: PT, NPT or PF?

PT is the stock thread on the three-way ball valve, the threaded swing check and both Y strainers, with NPT and PF made to order; the three-piece ball valve stocks PT, NPT and PF. For the two-piece valve and the spring check, tell us the thread you need and we will confirm what is on the shelf. Use the same standard for every position on the inquiry.

Is every valve tested before it ships?

Yes. Every valve is leak tested and checked for dimensions before shipment, whether it is a ball valve, a check valve or a strainer. The threaded swing check valve is also tested to API 598. A mill test report for the body material and a dimensional inspection report are available on request; name them on the inquiry so they are prepared with the order.

Is there a minimum order quantity for a mixed inquiry?

The minimum is settled in the quote rather than posted as one number for the range. It depends on the model and on the marking you ask for, since a laser-marked or private-labeled run is set up differently from a stock item. Send the quantities you actually need per position and we will quote against them, including small runs of the flanged check valve in mixed CF8 and CF8M.

Summary

To get the three positions on a line quoted together, send each position with its size, quantity, body grade, end connection and line conditions, and name the documents you want. A spreadsheet, a marked-up P&ID or a photo of the old valves is enough to start. SZ Valves, a stainless steel valve manufacturer in Taichung since 1995, quotes the list from one plant.

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