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Technical Parameters of Large Diameter Valves
| Parameter | Typical Specification |
|---|---|
| Size range | DN300 to DN1200 (12 inch to 48 inch); larger on project basis |
| Body construction | Sand cast CF8, CF8M, CF3M; fabricated from stainless plate for very large or low-pressure designs |
| Disc and stem | 304, 316L, duplex or coated disc; 17-4PH, 316 or duplex stem |
| Seat | EPDM, NBR, PTFE, metal seat, or integral rubber seat in wafer and lug designs |
| Pressure rating | PN6 to PN40, Class 150 and Class 300; AWWA Class 125B and 150B for waterworks |
| Flange standard | EN 1092-1, ASME B16.5 and B16.47 Series A or B, MSS SP-44, AWWA C207 |
| Working temperature | -10 °C to +120 °C with rubber seats; up to 200 °C or more with metal seats |
| Operation | Gearbox with handwheel, electric actuator, pneumatic or hydraulic actuator |
| Mounting | ISO 5211 for sizes up to F60; larger sizes by special flange |
| Surface protection | Pickled and passivated; epoxy coating on carbon steel parts |
Approximate weight guide
| Valve Type and Size | Approximate Weight Range |
|---|---|
| DN300 lug butterfly valve, PN16 | About 40 to 80 kg |
| DN600 lug butterfly valve, PN16 | About 200 to 350 kg |
| DN900 flanged butterfly valve, PN10 | About 700 to 1200 kg |
| DN300 flanged gate valve, Class 150 | About 250 to 400 kg |
| DN600 flanged gate valve, Class 150 | About 1200 to 2000 kg |
Weights are only a rough guide, since they vary with design and material. We send the exact weight and centre of gravity in the general arrangement drawing, so the contractor can plan lifting and supports.
Torque and actuator size. Torque needed to turn a large butterfly valve can be several thousand newton metres. We supply torque data with a safety factor, which helps select gearboxes or actuators correctly.
Large Diameter Valve Range and Accessories
A large valve is rarely supplied by itself. It comes with an operator, mounting kit, spacers, flanges, gaskets and sometimes a position indicator or limit switches. We supply the complete package so the valve can be installed and commissioned without hunting for missing items.
| Product | Size Range | Typical Use |
|---|---|---|
| Wafer and lug butterfly valve | DN300 to DN1200 | Cooling water, HVAC, general fluids |
| Flanged butterfly valve, concentric | DN300 to DN1600 | Water intakes, large headers |
| Double and triple offset butterfly valve | DN300 to DN1200 | Hot water, steam, process lines |
| Flanged gate valve | DN300 to DN1000 | Isolation on large lines |
| Dual plate wafer check valve | DN300 to DN1200 | Pump discharge, backflow prevention |
| Swing check valve | DN300 to DN1000 | Large pump lines |
| Trunnion mounted ball valve | DN300 to DN600 | High-reliability on-off service |
| Large strainers and spool pieces | DN300 to DN1000 | Protection of pumps and heat exchangers |
| Gearboxes, actuators, position switches | Matched to valve | Operation and monitoring |
Fabricated versus cast bodies
- Cast bodies: good for pressure-containing parts with complex shapes and higher ratings.
- Fabricated bodies: made from plate and rolled sections, suited to large, low-pressure butterfly valves and ducting, and can reduce weight and cost.
- Hybrid design: fabricated body with cast or forged end parts for special requirements.
When you send your requirements, we will recommend the construction that best fits pressure, size and delivery time.
Buyer tip: when you send the inquiry, include the pipe outside diameter, the flange standard and series, the medium, the maximum pressure and temperature, the operator type and the installation position. For large valves, a single sheet with these items usually allows us to prepare a drawing and a firm quotation in a few days, instead of weeks of questions.
Standards for Large Diameter Valves and Flanges
Large valves must follow both valve standards and flange standards, and these change across size ranges. Above DN600 or 24 inch, flange standards are different and sometimes less familiar. Please state the flange standard and the class clearly in your inquiry.
| Area | Standard Reference |
|---|---|
| Butterfly valve design | API 609, EN 593, AWWA C504 (rubber-seated, waterworks), ISO 5752 |
| Gate valve design | API 600, EN 1984, AWWA C500 for waterworks |
| Check valve design | API 594, EN 12334, BS 1868 |
| Ball valve design | API 6D, ISO 14313, API 608 |
| Flanges larger than DN600 | ASME B16.47 Series A and B, MSS SP-44, EN 1092-1 up to DN2000, AWWA C207 |
| Face-to-face length | EN 558, ASME B16.10, ISO 5752 |
| Pressure-temperature ratings | ASME B16.34, EN 12516 |
| Casting material | ASTM A351 CF8, CF8M, CF3M |
| Plate material | ASTM A240 304, 304L, 316, 316L |
| Welding | ASME Section IX, EN ISO 15614-1 |
| Testing | API 598, API 6D, EN 12266-1, ISO 5208 |
Series A or Series B. ASME B16.47 has two series of flanges for sizes 26 inch and above. Series A flanges are heavier and thicker, and Series B are lighter and more compact, with different outside diameter and bolting. They do not match, so state the series when you order.
If your project uses a waterworks standard such as AWWA, tell us in advance, because documentation, coating and marking rules are different from process standards.
Reference note: waterworks standards such as AWWA differ from process standards in design rules, coatings, marking and testing. If your project follows AWWA, say so early, since it changes the valve construction and the documents. We will tell you which parts of the standard we can follow and which need confirmation.
Certificates and Documentation for Large Valves
Large valves are usually project items, so documentation is organised project by project. We prepare a document list at the start, agree it with the buyer, and follow it through production. This avoids the usual last-minute rush to complete paperwork before the valves ship.
- Material test certificates: EN 10204 3.1 for body, disc, shaft, bonnet, bolting and plate, with heat numbers.
- Casting records: chemistry, heat treatment and mechanical tests, with NDE results.
- NDE reports: radiographic, ultrasonic, dye penetrant or magnetic particle reports for castings and welds, as specified.
- Welding documents: welding procedure specifications, procedure qualification records and welder qualifications for fabricated bodies.
- Dimensional report: flange dimensions, face-to-face length and critical clearances.
- Pressure test report: shell and seat tests, with gauge calibration records.
- Torque and function test report: operating torque and actuator test.
- Coating report: coating thickness and adhesion tests for carbon steel parts.
- Quality management: ISO 9001 style system, with inspection and test plans.
Inspection and test plan (ITP). For large valves, we recommend agreeing an ITP with hold and witness points before production begins. This lets your inspector attend the stages that matter, such as casting inspection, final machining, pressure test and packing, and avoids delays when the shipment date is close.
We can send sample ITPs and documentation lists for your review before order confirmation.
Audit tip: ask for a draft data book index at the start of the project. With it, your document controller can see which reports will arrive with the valve, and which need to be sent earlier, and can check the folder as items arrive rather than all at once after the valves land at the site.
Traceability for Large Castings and Fabricated Parts
Large valves are made of a small number of heavy parts, and each part has its own history. A DN800 body casting may take weeks to produce, and the records from melting, pouring, heat treatment and inspection must be kept with the casting. For fabricated bodies, each plate, each weld and each welder must be identified.
- Casting heat records: chemistry from the spectrometer and mechanical test bars from each heat, with heat number cast into the body.
- Plate traceability: mill certificates for each plate, with heat numbers transferred to cut parts before processing.
- Welding records: weld maps showing seam numbers, welder identity, procedure, consumable batch and inspection results.
- Heat treatment: furnace charts for solution annealing of castings and fabricated parts where needed.
- NDE map: locations and results of radiography, ultrasonic and penetrant inspections, filed with the valve serial number.
- Assembly record: body, disc, shaft, seat and bolting heat numbers listed in the assembly sheet.
| Item | Record | Purpose |
|---|---|---|
| Body casting | Heat number, chemistry, mechanical tests | Proof of material and strength |
| Plate parts | Mill certificate and heat number | Material identity after cutting |
| Welds | Weld map, WPS, welder, NDE | Evidence of weld quality |
| Disc and shaft | Heat number, hardness, PMI | Corrosion resistance and torque capacity |
| Finished valve | Serial number, test and coating reports | Complete dossier |
All records are collected into a data book for the valve, with one section per valve serial number. For a large order, the data book can run to hundreds of pages, so we agree its structure with the buyer in advance.
Testing Capability for Large Diameter Valves
Testing a large valve is a heavy operation. The test fixture must close both ends securely, the test water volume is large, and the valve must be handled with cranes. We have test equipment for large sizes, and we plan testing in advance to avoid delays at the end of production.
| Test | Typical Value or Method | Frequency |
|---|---|---|
| Shell test | Hydrostatic at 1.5 x rating, with hold time according to API 598 or EN 12266-1 | 100% of valves |
| Seat test | Hydrostatic at 1.1 x rating; for bidirectional valves, both directions | 100% of valves |
| Low-pressure air test | Air test for resilient-seated valves | 100% of soft-seated valves |
| Operating torque | Measured torque in both directions, compared with calculated values | 100% of valves with gear or actuator |
| Function test with actuator | Open and close cycles with the supplied actuator | 100% of actuated valves |
| NDE of castings | Radiography, ultrasonic or dye penetrant per specification | On request |
| Weld inspection | Visual, dye penetrant, radiographic or ultrasonic, for fabricated bodies | On request |
| Dimension inspection | Face-to-face, flange drilling, disc clearance, stem length | 100% of valves |
| Coating inspection | Thickness, adhesion, holiday test | 100% of coated parts |
Disc clearance and rotation. A large butterfly valve disc rotates with small clearance from the pipe bore, and a mismatch in pipe inner diameter or lining can cause jamming. We check disc travel on a mock flange, and ask for the pipe schedule or lining thickness to confirm clearance before shipment.
Witnessed testing can be arranged, and we recommend booking the date early, as the preparation of large tests takes time.
Frequently Asked Questions about Large Diameter Valves
Q: Which valve type is best for large diameter lines?
Butterfly valves are the most economical and compact for sizes above DN300. Gate valves suit full-bore isolation with low pressure drop, and check valves are used for pump discharge. Ball valves are used where high reliability and tight shut-off are needed.
Q: Can large valves be made from stainless steel plate?
Yes. For very large or low-pressure butterfly valves, fabricated bodies made of 304 or 316L plate are common, and they can reduce weight and delivery time compared with castings.
Q: What is the difference between flange Series A and Series B?
They are two flange series in ASME B16.47 for sizes 26 inch and above. Series A is heavier and thicker, and Series B is lighter, so they do not match each other.
Q: How are large valves lifted and installed?
They have lifting lugs or marked lifting points, and should be lifted by slings on the body, not on the actuator or stem. We supply weights, centre of gravity and lifting instructions.
Q: Do large butterfly valves need support?
Heavy valves and actuators need to be supported so the weight does not stress the flanges. Pipe supports near the valve are recommended, and we can supply guidance with the drawing.
Q: What actuators are used for large valves?
Gearboxes with handwheels, electric actuators, and pneumatic or hydraulic actuators. We size them based on calculated torque with safety factor, and can supply them mounted and tested.
Q: How long does it take to make a large valve?
Typically 45 to 90 days, depending on size, material and test requirements. Castings and NDE take the longest, so early order placement helps.
MOQ and Pricing for Large Diameter Valves
Large valves are project items, so we accept single pieces. Price is driven by weight and construction, and we quote each project individually, with a clear scope of supply.
| Item | Typical Terms |
|---|---|
| Sample or single piece | Accepted for large valves and replacement projects |
| Standard MOQ | 1 piece for DN300 and above; small lots for repeated sizes |
| Batch orders | Discount for 5 pieces or more of the same size |
| Special pattern or tooling | Quoted separately where needed |
| Pricing basis | EXW, FOB Ningbo, CFR or CIF in USD |
| Quote validity | 15 to 30 days, because material prices change |
| Payment | 30% T/T deposit, 70% before shipment; L/C at sight for approved accounts; milestone payments for large projects |
What drives the price
- Weight: material cost grows with the cube of diameter, so a DN1000 valve costs far more than a DN500 valve.
- Construction: fabricated bodies can be cheaper than castings for low-pressure butterfly valves.
- Material: 316L and duplex cost more than 304.
- Operator: gearboxes and electric actuators can be a large part of the total.
- Testing and NDE: radiography, ultrasonic examination and witnessed tests are priced separately.
- Packing and shipping: wooden cases, special frames and flat rack freight add cost.
Request a scope-of-supply sheet. For large orders, we prepare a sheet that lists exactly what is included, such as valve, operator, flanges, gaskets, coating, tests and documents, so that you can compare quotations on the same basis.
Ordering advice: for projects with several large valves, ask for a combined schedule and a price for the complete package, including operators and accessories. Large valves benefit from shared tooling and test set-up, and a clear schedule lets us book foundry, machining and testing slots well in advance.
Lead Time, Customisation, Packaging and Trade Terms
Lead time
Large diameter valves usually need 45 to 90 days, depending on size, material, NDE and testing. Fabricated butterfly valves may be faster, while heavy castings and duplex material take longer. We give a milestone schedule at order confirmation, covering pattern or plate, casting or fabrication, machining, testing, coating and shipping.
Customisation
We can customise flange standard and series, face-to-face length, body construction, disc and shaft materials, seat, coating system, gearbox or actuator, accessories, nameplate and documentation. For replacement projects, we can measure an existing valve, or work from drawings, to produce a matching unit.
Packaging and handling
- Flange faces and seats protected by wooden or plywood covers
- Valves packed with the disc in a partly open position, as recommended
- Wooden cases, steel frames or skids for heavy items, with lifting points marked
- Actuators protected and strapped separately where needed
- Labels showing weight, centre of gravity, project and tag number
Shipping and trade terms
| Term | Details |
|---|---|
| Incoterms | EXW, FOB Ningbo, CFR, CIF, DAP |
| Port | Ningbo-Zhoushan; Shanghai as an alternative |
| Transport | Sea freight, air freight for urgent items, express courier for samples |
| Documents | Invoice, packing list, bill of lading, origin certificate, material and test certificates |
For very large valves, we plan shipment using flat rack or open top containers, or break bulk where necessary, and we send loading photos and lifting instructions to help the receiving site prepare.
Site handling advice: before the delivery date, check access, crane capacity and storage area. Keep protective covers on until installation, support the valve properly during assembly, and never lift by the actuator or stem. We provide a short handling guide with each shipment, and are glad to answer questions from your installation crew.
