BS Resilient Seated NRS Gate Valve

Product Overview

The BS Resilient Seated Non-Rising Stem (NRS) Gate Valve is engineered to meet British Standards (BS 5163, BS EN 1074) for water and wastewater applications. Featuring a resilient EPDM or NBR seating and non-rising stem design, this valve provides bubble-tight shut-off while saving vertical installation space.

Unlike rising stem (RS) valves, the NRS design keeps the stem fully enclosed within the valve body during operation, making it ideal for installations with limited overhead clearance. The resilient seating ensures excellent sealing performance even in dirty or particulate-laden fluids.

Constructed with ductile iron body and stainless steel internal components, our BS NRS gate valve offers corrosion resistance and long service life—suitable for potable water, sewage, irrigation, and industrial utility systems.

Key Features & Benefits

Space-Saving Design

Non-rising stem (NRS) eliminates vertical stem extension, ideal for installations with limited overhead clearance.

Bubble-Tight Sealing

Resilient EPDM/NBR seating provides reliable shut-off even in dirty or particulate-laden fluids, meeting EN 12266-1 leakage class requirements.

BS Standard Compliance

Fully compliant with BS 5163, BS EN 1074, and WRAS-approved materials for potable water applications.

Bi-Directional Flow

Suitable for installation in any orientation, with equal performance in both flow directions.

Corrosion Resistance

Ductile iron body with epoxy coating and stainless steel internals ensures long service life in water and wastewater environments.

Low Operation Torque

Designed for easy manual operation or automation with electric, pneumatic, or hydraulic actuators.

Technical Specifications

Basic Parameters

Parameter	Specification Range
Nominal Diameter (DN)	DN40 ~ DN1200 (1.5" ~ 48") Common Sizes: DN50, DN80, DN100, DN150, DN200, DN300, DN400
Nominal Pressure (PN)	PN10, PN16 (10bar to 16bar)
Operating Temperature	-10°C ~ 80°C (Standard EPDM) -20°C ~ 120°C (Special Materials)
Applicable Media	Potable Water, Wastewater, Sewage, Irrigation Water, Cooling Water, Neutral Liquids
Sealing Class	EN 12266-1 Class A (Bubble-Tight)

Material Specifications

Component	Material Options	Standards/Features
Valve Body	Ductile Iron	EN-GJS-400-15, Epoxy Coated (Internal & External)
Disc	Ductile Iron with EPDM/NBR Liner	WRAS-Approved Elastomers for Potable Water
Stem	Stainless Steel	AISI 420 or 316, Non-Rising Design
Seats	EPDM, NBR, Viton	Resilient Seating, Corrosion & Abrasion Resistant
Fasteners	Stainless Steel	A2 or A4, Corrosion Resistant

Standards & Compliance

Design Standards: BS 5163, BS EN 1074-1, BS EN 1074-2
Flange Standards: BS 4504, BS EN 1092-1, PN10/PN16
Testing Standards: BS EN 12266-1, Hydrostatic and Leakage Testing
Certifications: WRAS, CE, ISO 9001

Working Principle

The BS Resilient Seated NRS Gate Valve controls fluid flow using a resiliently seated disc and non-rising stem mechanism:

Opening Process: Rotating the handwheel or actuator turns the stem, which raises the disc vertically within the valve body. The resilient seat compresses against the disc to form a tight seal when closed.
Closing Process: Reverse rotation lowers the disc onto the resilient seat, creating a bubble-tight seal. The non-rising stem design keeps the stem fully enclosed, preventing exposure to external elements.
Sealing Assurance: The resilient EPDM/NBR seating conforms to minor irregularities in the disc or body, ensuring reliable shut-off even in dirty or particulate-laden fluids.

Application Areas

Water Supply

Potable water distribution networks, municipal water systems, and water treatment plants.

Wastewater Treatment

Sewage systems, wastewater treatment plants, and stormwater management.

Irrigation

Agricultural irrigation systems, landscape irrigation, and greenhouse watering.

Industrial Utilities

Cooling water systems, process water lines, and general industrial applications.

Installation & Maintenance

Installation Guidelines

Inspect valve for damage and confirm closed position before installation; clean pipeline connections to remove debris.
Install in any orientation (bi-directional flow), ensure handwheel/actuator is accessible for operation.
Tighten flange bolts evenly in a crisscross pattern to avoid uneven pressure on the sealing surface.
Ensure sufficient space for maintenance, including access to the stem and actuator.
Conduct hydrostatic testing (1.5×PN) and leakage testing after installation before commissioning.

Maintenance Recommendations

Regularly inspect stem packing for leaks; adjust or replace packing as needed to maintain stem seal integrity.
Check resilient seating for signs of wear or damage; replace elastomers if necessary to maintain sealing performance.
Lubricate stem threads annually with approved grease to ensure smooth operation.
For long-term shutdown, keep valve fully open to prevent media from settling on seating surfaces.
Use only manufacturer-recommended replacement parts to maintain performance and compliance with standards.

Frequently Asked Questions (FAQ)

Q: What is the difference between RS and NRS gate valves?

A: RS (Rising Stem) valves have a stem that extends vertically when opened, providing visual position indication. NRS (Non-Rising Stem) valves keep the stem enclosed within the body during operation, ideal for space-constrained installations.

Q: Can resilient seated valves handle abrasive media?

A: Resilient seated valves are suitable for mildly abrasive media such as wastewater with small particulates. For highly abrasive applications, metal-seated valves are recommended.

Q: What is the maximum temperature rating for these valves?

A: Standard resilient seated NRS gate valves can operate up to 80°C with EPDM seating. For higher temperatures, contact our technical team for custom solutions.

Q: Are these valves suitable for potable water applications?

A: Yes, our BS Resilient Seated NRS Gate Valves are WRAS-approved and suitable for potable water use when equipped with EPDM or NBR seating materials.

Need Custom Solutions?

Our engineering team can customize BS Resilient Seated NRS Gate Valves to meet your specific pressure, temperature, and media requirements. Contact us today for a personalized quote.

Contact Our Technical Team