FAQ
Industrial Valve Sourcing: Frequently Asked Questions
Direct answers to the questions international distributors, EPC contractors and end users ask us most — valve selection, materials, standards, minimum order quantities, lead times, documentation, packing and after-sales support. Where an answer depends on your specific duty, we say so instead of guessing.
Quick answer (TL;DR)
JSZHUCAI exports butterfly, ball, gate, globe, knife gate, check and slurry valves to customers in more than 60 countries. Typical range: sizes from about 1.5" (DN40) to 66", pressure classes PN10–PN40 and Class 150–2500, bodies in cast iron, ductile iron, carbon steel and stainless steel 304/316. Standard items usually ship in 15–25 working days after order confirmation; trial orders are accepted. Quotations, dimensional drawings, material certificates and third-party inspection reports are available on request. We reply within 24 hours on business days.
Selection and application
How to match a valve to media, pressure, temperature and operating duty.
How do I choose the right valve for my application?
Start with five parameters: the medium, the maximum working pressure, the operating temperature, the line size, and how often the valve will be operated.
Media determines the body and seat material (see the material question below). Pressure and temperature together determine the pressure class, because a valve rated for Class 150 at ambient temperature is not rated for Class 150 at 300 °C. Line size and the space available decide whether a compact butterfly valve or a longer, straight-through gate valve is the practical choice. Operating frequency decides the operator: a valve cycled daily is usually fine with a lever or handwheel, while frequent or remote operation points to pneumatic or electric actuation. If you send us these five parameters we will propose a specification.
Butterfly valve or gate valve — which should I choose?
Choose a butterfly valve for compact installation, lower weight and lower cost at larger sizes. Choose a gate valve when you need a straight-through bore with minimal pressure drop and no obstruction of the flow path.
A butterfly valve occupies very little face-to-face length, which matters on large-diameter lines and in skids where space is tight. It is a quarter-turn valve, so it opens and closes quickly. A gate valve has a full-bore, straight-through path: the disc lifts completely out of the flow, so there is practically no pressure loss and a pig or scraper can pass. That makes gate valves common on pipelines, water mains and services where line cleaning or pigging is planned. Gate valves are taller because of the rising stem, and they should generally be used fully open or fully closed rather than for throttling. Butterfly valves, by contrast, are commonly used for both isolation and modulating control, especially in the double-offset and triple-offset ranges.
Which body material should I choose for seawater or corrosive media?
For seawater, a ductile iron body with a suitable internal coating, or a stainless steel 316 / duplex body where chloride resistance must be higher. For aggressive chemicals, the seat and disc material usually matters as much as the body.
Seawater is aggressive because of chlorides, and it attacks many standard grades. Cast iron is generally not recommended for continuous seawater service. Ductile iron with an appropriate coating is used in many cooling-water and fire-main applications, while stainless steel 316 (CF8M) and duplex grades give better resistance where the chloride level is high or the water is warm. For chemical service the wetted parts matter as a set: body, disc and seat. PTFE and PFA-lined options are commonly used for strong acids and alkalis, and elastomer seats such as EPDM and Viton cover a wide range of water, oil and general industrial duties. Always give us the exact medium and concentration so we can advise rather than generalise.
When do I need a metal-seated valve instead of a soft-seated valve?
Choose a metal seat for high temperature, abrasive media or fire-safe requirements. Choose a soft (elastomer or PTFE) seat when a bubble-tight shut-off at moderate temperature is the priority.
Soft seats — EPDM, Buna-N (NBR) and PTFE — give excellent sealing at low differential pressure and are the economical choice for water, air and general service. Their limit is temperature and abrasion. Our soft-seated ranges are typically rated from about −29 °C to 149 °C (−20 °F to 300 °F). Above that, and for abrasive slurries, a metal-to-metal seat is used. Our high-temperature metal-seated butterfly valves are rated for steam and hot process media up to 538 °C, and metal seating is also the choice where a fire-safe design is specified. A metal seat generally requires higher operating torque, so the operator has to be sized accordingly.
What is the difference between wafer, lug and flanged butterfly valves?
Wafer valves are clamped between two pipe flanges and are the most compact and lowest cost. Lug valves have threaded inserts so they can be bolted to a single flange — useful at the end of a line. Flanged valves have their own flanges and are the easiest to align and remove.
A wafer body has no threaded holes; it is sandwiched between the two pipeline flanges using through-bolts that pass from one flange to the other. That makes it short and economical, but it cannot be used as an end-of-line valve because removing the downstream flange leaves nothing to hold it. A lug body has threaded inserts on both sides, so it can be bolted to one flange and used for dead-end service or for maintenance where one side of the line is opened. A flanged (double-flanged) body carries its own flanges and bolts to each pipe flange separately, which gives the most robust connection and the simplest alignment on large sizes, at the cost of extra length, weight and price.
How do I select the correct pressure class?
Select the class from the maximum working pressure at the maximum operating temperature — not from the normal line pressure. Higher classes are heavier and more expensive.
Pressure classes such as Class 150 or PN16 are not a single number: they define a pressure–temperature rating, meaning the allowable pressure falls as temperature rises. A valve selected only on the cold line pressure can be under-rated at operating temperature. In practice, choose the class that covers your maximum working pressure at your maximum operating temperature, then check that the flange drilling matches the pipe flanges. Class 150 and PN16 cover a very large share of general water, air and light industrial duties; Class 300 and PN40 and above are used for higher-pressure process lines, and Class 900–2500 for critical high-pressure service.
Do I need pneumatic or electric actuation, and what about on/off versus modulating control?
For simple open/close duty, a pneumatic actuator with a solenoid valve is normally the most economical. For modulating control you also need a positioner. Electric actuation suits sites where compressed air is not available or where remote indication is required.
A pneumatic double-acting actuator needs air to open and to close, while a spring-return actuator fails to a defined position if air is lost — an important safety choice. Adding a solenoid valve gives electrical on/off control, and adding limit switches gives position feedback. Modulating (throttling) service needs a positioner so the actuator follows a control signal rather than simply moving to the end stops. Electric actuators are self-contained and are common where air is unavailable or where the valve is far from the plant air system. We can supply valves already assembled and tested with the actuator, positioner and accessories, so the assembly arrives matched to the valve torque.
Specifications, materials and standards
What is in our catalogue, and which standards apply.
Which materials do you supply?
Bodies: cast iron, ductile iron, carbon steel (WCB), stainless steel CF8 / CF8M (304 / 316), duplex and alloy steel. Seats: EPDM, Buna-N (NBR), PTFE, Viton and metal-to-metal.
The right combination depends on the medium, the temperature and the pressure. As a rule of thumb: cast iron and ductile iron for water, air and general services at moderate pressure; carbon steel for oil, gas and steam; stainless steel 304 and 316 where corrosion resistance is needed; duplex where chlorides are high; and alloy steel for high-temperature steam service. Seat material is chosen separately, because it controls both the temperature limit and the tightness of shut-off. The product page for each series lists the materials actually available for that model.
What size and pressure range is available?
Approximately 1.5" (DN40) up to 66", depending on valve type, with pressure ratings covering PN10, PN16, PN25, PN40 and Class 150 to 2500.
The available size range is different for each valve type — a resilient-seated butterfly valve and a triple-offset butterfly valve do not cover the same sizes and ratings. Small sizes are common for general service, while large diameters are typically used on water, cooling and utility lines. If you tell us the size and class you need, we will confirm which series covers it.
What temperature range can your valves handle?
Soft-seated valves typically operate from about −29 °C to 149 °C. Our high-temperature metal-seated butterfly valves are rated up to 538 °C for steam and hot process media.
The practical limit is set by the seat and seal material, not by the body alone. Elastomers such as EPDM and NBR have relatively low limits; PTFE extends the range; metal seating is used where the temperature or the fire-safe requirement rules out a polymer seat. Low-temperature service also needs attention, because some elastomers become brittle below about −30 °C. Always state the operating temperature range, not just the normal value, and we will confirm the seat material for the duty.
Which design standards do your valve ranges follow?
Our ranges are built to commonly referenced international standards including API 609, API 6D, API 600, API 594, MSS SP-67, MSS SP-70, EN 593 and ISO 5211, with pressure testing to API 598 or EN 12266-1 as applicable to the valve type.
Standards are not interchangeable: a butterfly valve and a gate valve follow different specifications, and face-to-face dimensions, flange drilling and top-works dimensions each come from their own standard. ISO 5211, for example, governs the mounting pad for the actuator. Because the applicable standard depends on the exact model, the product page or datasheet for the series you are buying is the authoritative reference — and we will always confirm the standard in the quotation for your order.
Can you supply valves to a specific face-to-face dimension or flange standard?
Yes. Flange drilling to ASME B16.5 / B16.47, EN 1092-1 / EN 1092-2, JIS and other standards can be provided, and face-to-face dimensions can be matched to your requirement subject to confirmation.
Face-to-face and flange compatibility is one of the most common reasons a valve will not fit an existing line. Tell us the standard you are replacing or the flange standard of your pipework, and we will check whether a standard catalogue item fits or whether a modified one is required. Such modifications are quoted individually because they affect tooling and lead time.
Can you produce a valve to my drawing?
Yes. We accept OEM and custom production to customer drawings and specifications, including private-label marking and packaging. We can sign a non-disclosure agreement before receiving sensitive documents.
Custom work normally starts with a drawing or a sample together with the required material, pressure rating, connection and quantity. Where new tooling or patterns are needed, tooling cost and lead time are quoted separately and confirmed before the order is placed. See our OEM & Custom page for the workflow.
Commercial terms
MOQ, lead time, payment, Incoterms and samples.
What is your minimum order quantity (MOQ)?
For standard specifications we accept trial orders starting from a small quantity. For customised production the MOQ depends on the specification and is confirmed with the quotation.
We deliberately keep the MOQ low for catalogue items so that a distributor can test the product before committing to volume. Customised valves carry a higher MOQ because tooling, patterns and production runs have to be set up for that specific design.
What is your production lead time?
Standard items are typically ready within 15–25 working days after order confirmation. Customised products may need longer, and the exact lead time is confirmed before you place the order.
Lead time starts from order confirmation and receipt of the agreed deposit, not from the enquiry date. Peak seasons and non-standard configurations can extend it. The confirmed lead time is stated in the proforma invoice so that it forms part of the order record.
What payment terms do you accept?
Our standard terms are a deposit with the balance against shipping documents. Exact terms depend on the order value and the trading history between us, and are agreed in the contract.
Payment terms are part of the commercial negotiation rather than a fixed published price list. For a first order the usual arrangement is a deposit on order and the balance settled against the copy of the shipping documents. For repeat customers we discuss terms that fit both sides.
What Incoterms do you quote?
We normally quote FOB, CIF or EXW. Tell us your destination port or address and we will quote the option that suits your logistics.
Under EXW and FOB, freight and insurance are for the buyer’s account unless otherwise agreed. Under CIF we arrange and pay the freight and insurance to the named destination port. We can also discuss DDP where we are able to arrange it. Import duties, taxes and clearance charges at destination remain the buyer’s responsibility unless the order is placed on DDP terms.
Can you supply a sample or trial order before I commit?
Yes — for most products we can supply a sample or a trial order. Sample and freight costs are normally charged and can be discussed.
A trial order is the practical way to verify dimensions, finish and performance before committing to volume. Tell us what you want to inspect and we will propose a suitable trial configuration.
Do you support OEM, private label and custom branding?
Yes. We produce to customer drawings and specifications and can apply customer branding, nameplates and packaging.
OEM work is handled through the same engineering route as any custom order: drawing or sample, specification confirmation, tooling if required, sample approval, then production. See our OEM & Custom page.
Documentation, testing and compliance
What we ship with an order, and what we deliberately do not claim.
What documentation is provided with a shipment?
Every shipment includes a packing list, commercial invoice and the bill of lading or airway bill. Dimensional drawings, material certificates, pressure test reports, third-party inspection reports and operation manuals are available on request.
Documentation is set out in the proforma invoice so it is clear before production starts what will be provided. If your customs authority or your customer requires a particular certificate or a legalised document, tell us at the enquiry stage so that we can confirm whether it can be provided.
Can you provide material certificates?
Yes, material certificates are available on request. The exact certificate type is confirmed with the quotation, because it depends on the material, the mill and the order.
A material certificate (mill test certificate) records the chemical composition and mechanical properties of the material actually used. The type and availability depend on the material and the supplier of the raw stock. We will state in the quotation which certificate can be provided for the specific material you are ordering, rather than promising a general certificate type in advance.
Which pressure and leak tests are carried out?
Valves are pressure tested — shell test and seat test — in accordance with API 598 or EN 12266-1 as applicable to the valve type. Test reports are available on request.
The shell test verifies the pressure-containing body; the seat test verifies the tightness of the closure. The applicable standard and the acceptance criteria depend on the valve type and the specification you ordered, which is why the test standard is stated per series rather than as a single blanket number.
Can I appoint a third party such as SGS, BV or TÜV to inspect my order?
Yes. Third-party inspection is welcome, and we can also arrange an inspection on your behalf. Inspection fees are normally for the buyer’s account.
If you appoint your own inspector, tell us the inspection scope and the required notice period so that the goods are ready and available at the agreed time. If you would like us to arrange it, we will obtain a quotation from the inspection body and confirm it with you before booking.
Are your valves CE marked?
Not as a blanket claim. CE marking applies to specific product categories and directives — for example the Pressure Equipment Directive for pressure equipment above certain limits, or ATEX for equipment intended for explosive atmospheres. Whether a particular valve requires CE marking depends on its rating and its intended market, so we assess it case by case and advise honestly rather than applying a general label.
This is exactly the kind of claim that should be verified rather than assumed. If your project or your market requires CE marking, tell us the application, the pressure and temperature limits and the destination country. We will confirm whether the directive applies, and where it does, we will state what documentation and marking can be supplied with the order. We do not describe every product as CE certified.
Packing, shipping and after-sales
How the goods are packed, shipped and supported.
How are valves packed for sea shipment?
Standard export packing is used: wooden cases or pallets with moisture protection, with the valve bore and flange faces protected. Custom marking and labelling can be applied on request.
Valve bores and flange faces are the surfaces most easily damaged in transit, so they are protected for the sea voyage. Larger valves are supplied on pallets or in cases sized for the container or for the customer’s handling equipment. If your warehouse or your customer requires a specific marking, label or pallet configuration, tell us before packing so it can be included.
Which ports do you ship from?
We normally ship from Shanghai and Ningbo, and can use other Chinese ports where the routing makes it worthwhile.
The port is chosen together with the Incoterm and the destination so that the total cost and transit time make sense. If you have a preferred carrier or a consolidation arrangement, we can work with it.
How long does shipping take?
As a guide from the date of shipment: Asia 7–20 days, Europe and the Mediterranean 25–40 days, North and South America 25–45 days, Africa and Oceania 20–45 days. Actual transit time depends on carrier schedules, port congestion, customs clearance and weather.
These figures are indicative port-to-port transit times and are not a contractual delivery date. We provide the bill of lading or airway bill together with the packing list and commercial invoice once the goods are dispatched, so that the shipment can be tracked.
What is the warranty?
Our products carry a 12-month warranty from the date of shipment against manufacturing defects under normal use. The warranty does not cover consumable parts, normal wear, or damage caused by improper installation, operation or maintenance.
The warranty runs from the date of shipment rather than the date of arrival or installation, which is the usual basis for export orders. Consumable parts and wear are excluded because they depend on the application. Full details are in our Return & Refund Policy.
What should I do if goods arrive damaged or short?
Note the damage or shortage on the carrier’s delivery receipt and notify us within 7 days, with photographs of the packaging and the product. Do not ship goods back before receiving an RMA number.
Recording the damage on the delivery receipt is important because it supports the freight claim against the carrier. Photographs of both the packaging and the product let us identify the cause quickly. Unauthorised returns may not be accepted, so always ask for an RMA number first.
How do I get a quotation?
Send us the medium, size, pressure class, operating temperature, connection type, body and seat material, quantity and destination port. We reply with pricing, lead time and shipping options within 24 hours on business days.
The more of these parameters you provide, the more precise the quotation and the fewer rounds of clarification are needed. A drawing or a photograph of the nameplate of the valve you are replacing is often the fastest way to get an accurate answer.
Did not find your question?
Send us your requirement — medium, size, pressure and temperature, or the machine and job — and our sales engineers will reply within 24 hours on business days. For urgent technical questions, WhatsApp is the fastest channel.