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Product Overview

The Stainless Steel Threaded Check Valve is a small‑bore check valve with an all‑stainless‑steel body and female threaded ends, widely used in petrochemical, chemical, pharmaceutical, food, water treatment, and instrumentation piping systems. Based on the structural design, it is mainly divided into Swing Type and Spring‑Loaded Type (Lift / Ball Type) :

1. Swing Type: The disc rotates around a pin shaft and closes by gravity and backpressure. It offers low flow resistance and is suitable for clean media and horizontal pipelines.

2. Spring‑Loaded Type: The disc is assisted by a spring for closing, providing rapid response and allowing installation at any angle.

Both types offer strong corrosion resistance, easy installation, and reliable sealing, allowing flexible selection according to operating conditions.

 Product Structure

Common Features:

1. Body: Precision cast stainless steel (CF8/304 or CF8M/316) with female threaded ends (NPT, BSPT, BSPP, G, etc.).

Swing Type Construction:

1. Disc: Stainless steel circular disc rotating around a top or eccentric pin shaft; sealing face can be hardfaced or covered with PTFE.

2. Pin Shaft: Stainless steel shaft; no spring – disc closes by gravity and backpressure.

3. Seat: Metal‑to‑metal or soft seat (PTFE/PEEK).

Spring‑Loaded Type Construction:

1. Disc: Stainless steel ball, conical, or flat disc; PTFE overlay optional.

2. Spring: Stainless steel coil spring providing preload for rapid closing.

3. Seat: Metal seat or inserted soft seat (PTFE, FKM, EPDM).

4. Guide Structure: Ensures axial movement of the disc without tilting.

The swing type is slightly longer with a more unobstructed flow path; the spring‑loaded type is more compact and can be installed at any angle.

 Function

Common Functions:

1. Prevents Backflow: Forward flow opens the disc; reverse flow or flow stoppage makes the disc close quickly, stopping backflow.

2. High Corrosion Resistance: All‑stainless‑steel (304/316) resists water, oil, weak acids, alkalis, salt spray, and many chemicals.

3. Clean Design: Smooth internal bore, suitable for sanitary applications in food and pharmaceutical industries.

Swing Type Features:

1. Low Flow Resistance: When fully open, the disc lies flat, providing minimal pressure loss.

2. No Spring Fatigue: Simple structure, long service life.

3. Installation Restriction: Horizontal pipeline only (hinge at top).

Spring‑Loaded Type Features:

1. Any‑Angle Installation: Horizontal, vertical, or inclined (vertical installation requires upward flow).

2. Rapid Closing: Spring provides instant closing force, reducing water hammer.

3. Low Opening Pressure: Optimized spring stiffness, opening pressure approx. 0.01–0.05 MPa.

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Working Conditions

1. Applicable Media: Water, oil, gas, steam, weak acids/alkalis, solvents, chemicals, food pastes (sanitary grade), etc.

2. Temperature Range: –29°C to +200°C (PTFE seals); –29°C to +400°C (metal seated).

3. Pressure Rating: PN16, PN25, PN40, PN63 (Class 150, 300, 600).

4. Installation Position:

   1. Swing Type: Horizontal pipeline (recommended); not to be installed upside down.

   2. Spring‑Loaded Type: Any angle (vertical requires upward flow).

5. Typical Applications:

   1. Chemical pump discharges

   2. Food & beverage production lines

   3. Pharmaceutical purified water systems

   4. Laboratory and instrument piping

   5. Hydraulic system return lines

   6. Compressed air branch lines

   7. Marine and offshore piping

 Summary

The Stainless Steel Threaded Check Valve is available in Swing Type and Spring‑Loaded Type to meet different installation conditions and performance requirements:

1. Swing Type: Low flow resistance, no spring fatigue, suitable for horizontal pipelines and high‑temperature applications. It is an economical choice for clean media and steam systems.

2. Spring‑Loaded Type: Any‑angle installation, rapid closing, reliable sealing. Ideal for space‑limited or vertical installation scenarios.

Both types feature an all‑stainless‑steel corrosion‑resistant body and compact threaded connections, widely used in chemical, food, pharmaceutical, and general industrial small‑bore pipelines. Whichever type is selected, the Stainless Steel Threaded Check Valve provides long‑term, maintenance‑free backflow protection and is a standardized safety component for small‑bore piping systems.