Download Catalog

A Non-Return Valve (NRV)—also called a Check Valve—is a valve that allows fluid (liquid or gas) to flow in only one direction and automatically prevents reverse flow. It is widely used in pumps, pipelines, water systems, oil & gas, and industrial processes.

Below is a clear engineering breakdown of types, specifications, working details, materials, standards, and typical prices.

---

🔧 TYPES OF NON-RETURN VALVES (NRV)

1. Swing Check Valve

✔ Working Principle

• A hinged disc swings open with forward flow

• Closes by gravity/backflow pressure

📊 Technical Specifications

• Size: DN50 to DN1200+

• Pressure: PN10 / PN16 / Class 150–300

• Material: Cast Iron, Ductile Iron, Carbon Steel, SS304/316

• End connection: Flanged / Wafer

• Temp range: -10°C to 200°C

✅ Features

• Low pressure drop

• Best for large pipelines

• Risk of water hammer (in fast reverse flow systems)

💰 Price Range (India)

• ₹800 – ₹15,000 (small to medium sizes)

• ₹15,000 – ₹1,00,000+ (large industrial)

---

2. Lift Check Valve (Piston Type)

✔ Working Principle

• Disc/piston lifts vertically with pressure

• Falls back to seat when flow stops

📊 Technical Specifications

• Size: DN15 to DN300

• Pressure: Class 150–600

• Material: Stainless steel / Carbon steel

• End connection: Threaded / Flanged

• Cracking pressure: 0.05–0.5 bar (typical)

✅ Features

• Better sealing than swing type

• Suitable for vertical pipelines

• Higher pressure handling

💰 Price Range

• ₹1,200 – ₹25,000 depending on size & material

---

3. Ball Check Valve

✔ Working Principle

• A ball moves to block reverse flow

• Flow pushes ball off seat

📊 Technical Specifications

• Size: DN8 to DN100

• Pressure: PN10–PN40

• Material: Brass, SS, PVC, PP

• Orientation: Horizontal/vertical

✅ Features

• Self-cleaning design

• Works well with viscous fluids

• Compact size

💰 Price Range

• ₹300 – ₹8,000

---

4. Dual Plate (Wafer) Check Valve

✔ Working Principle

• Two spring-loaded plates open centrally

• Close quickly when flow reverses

📊 Technical Specifications

• Size: DN50 to DN600+

• Standard: API 594

• Pressure: Class 150–2500

• Material: SS, WCB, duplex steel

✅ Features

• Fast closing (anti water hammer)

• Compact and lightweight

• Very common in industrial plants

💰 Price Range

• ₹2,000 – ₹80,000+

---

5. Diaphragm Check Valve

✔ Working Principle

• Flexible rubber diaphragm opens under pressure

• Automatically seals on reverse flow

📊 Technical Specifications

• Size: DN15–DN300

• Material: Rubber (EPDM, NBR), PTFE lining

• Pressure: Low to medium (PN6–PN16)

• Applications: Slurry, chemicals, wastewater

✅ Features

• Good for corrosive fluids

• Handles solids/slurry

• Low maintenance

💰 Price Range

• ₹500 – ₹20,000

---

📊 GENERAL INDUSTRY SPECIFICATIONS (COMMON FOR ALL NRVs)

Parameter	Typical Range
Design Standards	API 594, BS 1868, EN 12334
Pressure Rating	PN6 – PN420 / Class 150–2500
Temperature	-50°C to 450°C (based on material)
Materials	CI, DI, CS, SS304, SS316, Bronze
Media	Water, steam, oil, gas, chemicals
Function	Prevent backflow automatically

---

⚙️ KEY TECHNICAL TERMS

• Cracking Pressure: Minimum pressure needed to open valve

• Pressure Drop: Loss of pressure across valve

• Water Hammer: Shock due to sudden closure

• Seating: Seal between disc and body

• Flow Direction: Always indicated by arrow on body

---

💰 PRICE SUMMARY (INDIA MARKET OVERVIEW)

Type	Approx Price Range
Swing Check Valve	₹800 – ₹1,00,000+
Lift Check Valve	₹1,200 – ₹25,000
Ball Check Valve	₹300 – ₹8,000
Dual Plate Valve	₹2,000 – ₹80,000+
Diaphragm Valve	₹500 – ₹20,000

(Prices vary by brand, pressure class, and material like SS316 or carbon steel.)

---

📌 QUICK SELECTION GUIDE

• 🏭 Large pipelines → Swing Check Valve

• ⚙️ High pressure systems → Lift Check Valve

• 💧 Water pumps / compact systems → Ball Valve

• 🚀 Industrial plants (fast closure) → Dual Plate Valve

• 🧪 Chemicals/slurry → Diaphragm Valve

---