Product Name
304 One-Piece Silent Check Valve
Product Summary
A one-piece silent check valve (spring check valve) in cast 304 stainless steel — the spring closes the piston before flow reverses, stopping water hammer and protecting pumps and pipes. Female PT threads in stock, sizes 1/2″–2″; NPT and PF threads and a 316 (CF8M) version made to order. The compact one-piece body fits tight spaces.
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ISO 9001 · CE · Manufacturer since 1999
Product Description
The SC-1 is a one-piece silent check valve — also sold as a spring check valve or inline check valve. A stainless spring pushes the piston closed before flow fully reverses, so the valve shuts quietly instead of slamming: no water hammer, no shock load on pumps and pipes. The one-piece body is compact enough for tight spaces around pumps and manifolds.
The body, piston and cap are cast 304 stainless steel (CF8), with a CF8M (cast 316) version made to order. Female PT threads are in stock, sizes 1/2″ to 2″; NPT and PF can be made to order. Prefer a hinged-disc valve with lower pressure drop? See the stainless steel swing check valve, or browse all stainless steel check valves.
Silent (Spring) or Swing — Which Check Valve?
| Silent / spring check (this valve) | Swing check | |
|---|---|---|
| Closing action | A spring closes the piston before flow fully reverses (non-slam) | Gravity and reverse flow swing the hinged disc shut |
| Pressure drop | Higher — the spring sits in the flow path | Low — the disc swings clear of the bore |
| Best for | Pump discharge and lines prone to water hammer | General water, oil and gas lines where low pressure drop matters |
Key Technical Specifications
| Type | Silent check valve — one-piece, spring loaded (inline / spring check valve) |
| Model | SC-1 |
| Size range | 1/2″ – 2″ |
| Body, piston & cap | CF8 — the cast form of 304 stainless steel — in stock; CF8M (cast 316) made to order |
| Spring | SS304 (SS316 on the 316 version) |
| End connection | Female PT thread — in stock; NPT and PF made to order |
| Construction | One-piece body, compact face-to-face |
Materials
Four parts, matching the numbered circles ①–④ in the drawing below. Materials shown for the 304 version in stock; the made-to-order 316 version uses CF8M castings and an SS316 spring.
| No. | Part | Material |
|---|---|---|
| 1 | Body | CF8 (CF8M to order) |
| 2 | Piston | CF8 (CF8M to order) |
| 3 | Spring | SS304 (SS316 to order) |
| 4 | Cap | CF8 (CF8M to order) |
Dimensions (mm)
Female PT threads in stock; NPT and PF made to order. Full drawing in the 1PC Check Valve dimension sheet (PDF).
| Size | B | C | D |
|---|---|---|---|
| 1/2″ | Ø25 | 56 | Ø27 |
| 3/4″ | Ø31.9 | 62.4 | Ø33.9 |
| 1″ | Ø38 | 71.5 | Ø39.2 |
| 1-1/4″ | Ø48.5 | 80 | Ø50.5 |
| 1-1/2″ | Ø55 | 92 | Ø57.5 |
| 2″ | Ø67 | 102 | Ø70 |
Application Fields & Locations
- Pump discharge lines: the spring closes the valve before backflow builds up, protecting pumps from water hammer and reverse spin.
- Water treatment & supply lines: quiet check duty where slam noise is unacceptable.
- Tight installations: the short one-piece body fits manifolds and cramped piping where a swing check will not.
FAQ
Why is it called a silent check valve? Because it closes quietly. The spring pushes the piston shut before flow fully reverses, so there is no rush of backflow to slam the valve — the bang known as water hammer never happens.
Is this the same as a spring check valve or inline check valve? Yes — silent check valve, spring check valve and inline check valve are different names for the same design: a spring-loaded piston inside a straight one-piece body.
Silent or swing check — which one do I need? Choose this silent type for pump discharge and lines prone to water hammer. Choose the swing check valve where low pressure drop matters more — its disc swings fully clear of the bore.
What material is it? Body, piston and cap are cast 304 stainless steel (CF8) with a SS304 spring — in stock. A 316 version (CF8M castings, SS316 spring) is made to order.
Which thread standards are available? Female PT threads are in stock, sizes 1/2″–2″. NPT and PF can be made to order — tell us which standard your piping uses when you request a quote.
What is the minimum order? No minimum order quantity — we accept orders of any size, including small trial orders. For small orders, freight is arranged and paid by the buyer. Payment is by T/T — 30% on order confirmation, 70% before shipment.
Sample Policy
We are happy to provide product samples for customers to evaluate quality or conduct testing. The process typically begins with a quotation based on the customer’s specifications.
If the pricing is acceptable, we can offer samples either free of charge or at a cost depending on the product type and availability.
Shipping fees are borne by the customer.
Order Process
After confirming the product requirements and other details with the customer, we will issue a Sales Confirmation for approval. Once confirmed, the customer is required to pay a 30% deposit to proceed with production.
When mass production is completed and the goods pass inspection, the customer must pay the remaining 70% balance before shipment is arranged.
Related Products
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Stainless Steel Check Valves304 Flanged Check Valve 10K / 150#
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Stainless Steel Check ValvesStainless Steel Swing Check Valve, 200 WOG – PT Threaded (Non-Return)
FAQ
A. How can I request a quote?
Please provide a detailed inquiry sheet including product specifications, materials, quantities, and any special requirements. We will offer a quotation based on your request.
B. What are your quotation terms?
Our quotations are typically based on FOB terms. However, we can also offer CFR, CIF, or other Incoterms upon request.
C. What is your Minimum Order Quantity (MOQ)?
We have no MOQ. We operate on a made-to-order basis and accept orders of any size — trial orders are welcome. For smaller orders, freight is arranged and borne by the buyer.
D. What are your payment terms?
By T/T – 30% down payment upon order confirmation, and 70% balance before shipment.
E. What is your lead time?
Lead time depends on order quantity and specifications. We will confirm the exact schedule when you request a quote.
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