CI Wafer Type NRV PN16 Water Treatment Valve
The industry-standard CI wafer type NRV PN16 water treatment solution. Engineered for WTP, ETP, and STP pump discharge protection. IS 210 Cast Iron body, EPDM/NBR seats, and 16-bar pressure rating. API 598 hydrostatic tested with full MTC. Best bulk pricing for Indian EPC contractors and municipal water boards.
Quick Answer: A CI wafer type NRV PN16 is a cast iron non-return valve (check valve) rated for 16 bar working pressure, clamped between two pipeline flanges. It is the most specified valve for Indian water treatment plants (WTP, ETP, STP) because the IS 210 FG200/FG260 cast iron body offers optimal durability against water hammer, while the PN16 rating safely handles standard centrifugal pump discharge pressures. The wafer design reduces weight by 40% compared to flanged NRVs, saving structural support costs in large pump houses.
At-A-Glance Specifications
Contents
- 1. Why CI Wafer Type NRV PN16 is the Standard for Water Treatment
- 2. Material Construction & Grade Specifications
- 3. Seat Selection: EPDM vs NBR for Water Treatment
- 4. Face-to-Face Dimensions & Pressure Ratings
- 5. Installation & Maintenance in Pump Houses
- 6. Applications: WTP, ETP, STP & Municipal Water
- 7. Why EPCs & Water Boards Choose KELOR
- 8. Frequently Asked Questions (FAQ)
Why CI Wafer Type NRV PN16 is the Standard for Water Treatment
When designing or procuring valves for water treatment infrastructure in India, the CI wafer type NRV PN16 water treatment configuration is the undisputed industry baseline. Here is why plant engineers and EPC contractors specify this exact combination:
- Cost-to-Durability Ratio: Cast Iron (IS 210) provides excellent tensile strength and water hammer resistance at a fraction of the cost of Ductile Iron or Stainless Steel. For non-corrosive water and sewage, CI is the most economical choice.
- PN16 Pressure Rating: Standard centrifugal pumps in Indian WTPs and STPs operate between 6 to 12 bar. PN16 (16 bar) provides a mandatory 30-40% safety margin for pressure surges and water hammer during sudden pump trips.
- Wafer Design Efficiency: Wafer NRVs are clamped between flanges, making them 40% lighter and shorter than lug or flanged end NRVs. This reduces pipeline weight, minimizes the need for heavy pipe supports, and saves critical space in crowded pump houses.
- Spring-Assisted Closure: Unlike swing check valves, wafer type NRVs use a spring to close the disc rapidly before flow reversal occurs. This prevents water hammer, protecting expensive pumps and pipeline joints.
Material Construction & Grade Specifications
Using substandard cast iron leads to graphitic corrosion and sudden valve failure. KELOR strictly uses virgin IS 210 FG200/FG260 cast iron, ensuring consistent mechanical properties and leak-proof performance.
Body and Disc Materials
| Component | Standard Material Grade | Properties & Benefits |
|---|---|---|
| Body | Cast Iron IS 210 FG200 / FG260 | High tensile strength, excellent vibration damping, cost-effective for water service. |
| Disc (Plates) | Cast Iron / SS304 / SS316 | CI for standard water; SS304/316 upgrade available for chemically treated water. |
| Seat (Liner) | EPDM / NBR (Nitrile) | EPDM for clean/treated water; NBR for raw water, sewage, and oily effluents. |
| Spring | SS304 / SS316 | Stainless steel springs prevent rusting and ensure consistent closing torque over years. |
| Shaft / Hinge Pin | SS304 / SS316 | Corrosion-resistant pivot points for smooth, friction-free disc movement. |
Procurement Tip for EPC Contractors
Always specify IS 210 FG200 or FG260 in your tender BOQ. Avoid “commercial grade” or recycled cast iron, which is brittle and prone to cracking under water hammer. Demand an EN 10204 3.1 Material Test Certificate (MTC) with every batch to verify the chemical composition and tensile strength.
Seat Selection for Water Treatment NRV
The elastomer seat provides the bubble-tight shut-off. Choosing the wrong seat for your specific water treatment stream will result in premature degradation, leakage, and costly downtime.
| Seat Material | Best For (Application) | Avoid For | Temp Range |
|---|---|---|---|
| EPDM | WTP: Potable water, treated water, cooling water, DM water. Excellent resistance to ozone and chlorinated water. | Oils, hydrocarbons, grease, raw sewage with high fat content. | -10°C to +80°C |
| NBR (Nitrile) | ETP/STP: Raw water, sewage, sludge, oily wastewater, industrial effluents. Superior resistance to abrasion and hydrocarbons. | Highly chlorinated water, ozone-treated water, strong oxidizers. | -10°C to +80°C |
Face-to-Face Dimensions & Pressure Ratings
KELOR CI wafer type NRVs conform to ISO 5752 Series 19 (short pattern) and API 594 standards, ensuring direct retrofitting into existing pipelines without modifying flange spacing.
Table: Standard PN16 Face-to-Face Dimensions (mm)| Size (DN) | 50 | 80 | 100 | 150 | 200 | 250 | 300 | 400 | 500 | 600 |
|---|---|---|---|---|---|---|---|---|---|---|
| Face-to-Face (mm) | 43 | 46 | 52 | 56 | 60 | 68 | 78 | 102 | 127 | 140 |
| Weight Approx (kg) | 1.5 | 2.5 | 3.5 | 6.0 | 9.0 | 14.0 | 20.0 | 38.0 | 60.0 | 85.0 |
Note: PN10 and PN16 share the same face-to-face dimensions. PN16 valves have thicker body walls and heavier flange drilling to safely handle the higher 16-bar pressure.
Installation & Maintenance in Pump Houses
Correct Orientation
CI wafer NRVs can be installed horizontally or vertically. For vertical installation, flow must be upward. Always align the flow direction arrow cast on the valve body with the pipeline flow direction.
Flange Bolting
Use a full set of high-tensile stud bolts and nuts. Never use a partial bolt set. Tighten bolts in a star pattern to ensure uniform compression of the wafer body and prevent leakage at PN16 pressures.
Preventing Water Hammer
Ensure the NRV is installed as close to the pump discharge as possible (within 1 to 2 pipe diameters). This minimizes the volume of water that can reverse flow, drastically reducing water hammer impact.
Routine Maintenance
Wafer NRVs are virtually maintenance-free. However, in STP/ETP applications with high suspended solids, inspect the seat annually for abrasive wear. Replace the seat liner if leakage exceeds API 598 limits.
Applications: WTP, ETP, STP & Municipal Water
Municipal Water Treatment (WTP)
Raw water intake pumps, clarifier outlets, filtration bed isolation, and clear water reservoir discharge. EPDM seated CI NRVs are the standard for Jal Jeevan Mission and AMRUT projects.
Sewage and Effluent Treatment (STP/ETP)
Sewage transfer pumps, aeration tank recirculation, sludge return lines, and chemical dosing lines. NBR seated CI NRVs handle the abrasive nature of raw sewage and suspended solids effectively.
Cooling Water & HVAC Systems
Condenser water pumps, cooling tower isolation, and chilled water circuits. Prevents reverse flow and gravity drain-back when pumps are shut down.
Why EPCs & Water Boards Choose KELOR
Strict IS 210 Compliance
We do not use recycled scrap iron. Every CI body is cast from virgin IS 210 FG200/FG260, ensuring high tensile strength and zero porosity. MTC provided with every batch.
100% API 598 Tested
Every single valve undergoes shell and seat hydrostatic testing at 1.5x and 1.1x PN16 pressure respectively. Test certificates are included in the dispatch documentation.
Project Tender Support
We supply for government water tenders (Jal Jeevan, AMRUT, state PHED). We provide GST invoices, E-Way bills, third-party inspection (TUV/BV/Lloyd’s), and complete QA dossiers.
PAN India Fast Dispatch
Standard CI wafer NRV sizes (DN50 to DN300) are kept in bulk stock at our Ahmedabad warehouse. Dispatch within 3-5 working days via VRL, TCI, or Professional Courier.
Commercial & Ordering Details
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Frequently Asked Questions (FAQ)
1. Why is CI Wafer Type NRV PN16 the standard for water treatment plants in India?
2. Should I use EPDM or NBR seats for my water treatment NRV?
3. What is the difference between a wafer type and lug type NRV?
4. Do you supply CI wafer NRVs for government water tenders?
5. What is the MOQ and delivery time from Ahmedabad?
Specify KELOR CI Wafer NRVs
IS 210 certified cast iron, 100% hydrostatically tested, and dispatched PAN India.
- IS 210 FG200/FG260 Virgin Cast Iron
- PN16 (16 Bar) Pressure Rating
- EPDM (WTP) / NBR (STP) Seats
- API 598 Tested with MTC
- 3-5 Day Dispatch from Ahmedabad