BS Metal Seated NRS Gate Valve

Product Overview

The BS Metal Seated Non-Rising Stem (NRS) Gate Valve is engineered to meet British Standards (BS 5163, BS EN 1074) for industrial, power, and high-temperature applications. Featuring a metal-to-metal seating and non-rising stem design, this valve provides reliable shut-off in demanding environments.

Unlike rising stem (RS) valves, the NRS design keeps the stem enclosed within the body during operation, making it ideal for space-constrained installations. The metal seating ensures excellent durability and performance in high-temperature and abrasive conditions.

Constructed with carbon steel or stainless steel body and internal components, our BS NRS gate valve offers high-temperature resistance and long service life—suitable for steam, oil, gas, and industrial process systems.

Key Features & Benefits

Space-Saving Design

Non-rising stem (NRS) design keeps the stem enclosed within the body, making it ideal for installations with limited vertical space.

High-Temperature Resistance

Metal-to-metal seating allows operation in high-temperature environments up to 425°C, suitable for steam and hot oil applications.

BS Standard Compliance

Fully compliant with BS 5163, BS EN 1074, and API 600 standards for industrial valve applications.

Bi-Directional Flow

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

Corrosion & Abrasion Resistance

Carbon steel or stainless steel construction with hardfaced seating ensures long service life in corrosive and abrasive environments.

Easy Automation

Designed for easy integration with electric, pneumatic, or hydraulic actuators for automated operation.

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)	PN16, PN25, PN40 (16bar to 40bar)
Operating Temperature	-20°C ~ 425°C (Carbon Steel) -196°C ~ 600°C (Stainless Steel)
Applicable Media	Steam, Oil, Gas, Water, Chemicals, Abrasive Fluids
Sealing Class	EN 12266-1 Class B (Metal-to-Metal)

Material Specifications

Component	Material Options	Standards/Features
Valve Body	Ductile & Casting Iron,Carbon Steel, Stainless Steel	ASTM A216 WCB, ASTM A351 CF8/CF8M, Flanged or Butt Welded
Disc	Ductile & Casting Iron,Carbon Steel, Stainless Steel	Hardfaced with Stellite or Chrome Alloy for Wear Resistance
Stem	Stainless Steel	AISI 410 or 316, Non-Rising Design with Bronze Bushing
Seats	Stellite, Chrome Alloy	Metal-to-Metal Seating, Fire-Safe Design
Fasteners	Stainless Steel	A193 B7/B8, Corrosion Resistant

Standards & Compliance

Design Standards: BS 5163, BS EN 1074-1, BS EN 1074-2, API 600
Flange Standards: BS 4504, BS EN 1092-1, PN16/PN25/PN40
Testing Standards: BS EN 12266-1, API 598, Hydrostatic and Leakage Testing
Certifications: CE, ATEX, ISO 9001

Working Principle

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

Opening Process: Rotating the handwheel or actuator turns the stem, which raises the disc vertically. The non-rising stem remains enclosed within the valve body, providing a compact design.
Closing Process: Reverse rotation lowers the disc onto the metal seat, creating a tight seal. The stem does not extend outside the body, making it suitable for space-constrained installations.
Sealing Assurance: The metal-to-metal seating provides excellent durability and performance in high-temperature and abrasive conditions, ensuring reliable shut-off even in demanding environments.

Application Areas

Power Generation

Steam turbines, boiler systems, and power plant cooling water lines.

Oil & Gas

Crude oil pipelines, refineries, and natural gas processing plants.

Chemical Processing

Chemical plants, petrochemical facilities, and pharmaceutical manufacturing.

Water & Wastewater

Industrial wastewater treatment, desalination plants, and large-diameter water pipelines.

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 sufficient space for operation and maintenance.
Tighten flange bolts evenly in a crisscross pattern to avoid uneven pressure on the sealing surface.
Ensure handwheel/actuator is accessible for operation and maintenance.
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 metal seating for signs of wear or damage; resurface or replace seats if necessary to maintain sealing performance.
Lubricate stem threads annually with high-temperature 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 NRS and RS gate valves?

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

Q: Can metal seated valves handle high temperatures?

A: Yes, metal seated valves are designed for high-temperature applications up to 425°C (carbon steel) or 600°C (stainless steel), making them suitable for steam and hot oil systems.

Q: Are metal seated valves suitable for abrasive media?

A: Yes, metal seated valves with hardfaced seating (Stellite or Chrome Alloy) are suitable for abrasive media such as slurry, ash, and other particulate-laden fluids.

Q: What is the fire-safe rating for these valves?

A: Our BS Metal Seated NRS Gate Valves are designed to meet API 607 and API 6FA fire-safe standards, ensuring reliable performance in fire conditions.

Need Custom Solutions?

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

Contact Our Technical Team