Bray Series 941 Unidirectional Knife Gate Valve, NPS 2 to 24

A self-draining lug valve for dirty, abrasive and hot media

The Bray Series 941 is a unidirectional knife gate valve for general-purpose on/off service and isolation of clean, dirty, corrosive, abrasive, viscous and high-temperature media. Its single-piece lug body in CF8M (316) stainless steel has no dead pockets, so the valve drains itself, and the lugs allow every mounting orientation including dead-end service. The brochure headline range is NPS 2 to 24 at 150 psi (10 bar).

Where the Series 740 relies on a resilient seat for bidirectional sealing, the 941 uses a standard integral metal seat with an optional replaceable zero-leakage resilient seat. The gate edges are rounded to lengthen packing life, and the packing is an energized quad seal with a PTFE anti-extrusion ring as standard. Bray lists its uses as pulp and paper stock and liquor lines, pneumatic conveyance, raw and treated water, fly ash and bottom ash branch lines in power plants, slurry and sludge lines in wastewater, chemical pellets and process fluids, petroleum products, food and beverage storage, and non-hard-rock mining such as lithium and cobalt.

Technical specifications

Source: Bray brochure EN_V-6006_S941 and recommended specification sheet EN_RSS_941. Where the brochure ranges differ (NPS 2 to 24 versus 2 to 36), confirm the size and rating with Bray before ordering.

Packing temperature and what the deflection cone does

Packing choice sets the maximum temperature. Bray prints pure PTFE to 500 deg F (260 deg C), PTFE-impregnated synthetic fiber to 450 deg F (232 deg C), quad-seal combinations with Buna-N to 194 deg F (90 deg C), Viton to 392 deg F (200 deg C) or EPDM to 248 deg F (120 deg C), and graphite packing to 1202 deg F (650 deg C). The metal seat is what lets the 941 follow these temperatures where a resilient seat could not.

For normally open abrasive service Bray offers a deflection cone, fitted between valve face and pipe flange to redirect flow away from the seat. It is made in 25 percent chrome iron for abrasive duty or in polyurethane for abrasive and corrosive duty, is field replaceable, and fits the unidirectional Series 940, 941 and 950. Typical uses printed by Bray are fly ash hopper outlets, cyclone isolation, pump suction, slurry tanks and ore handling.

Choosing between unidirectional knife gate series

Pick the 941 when flow is in one direction, the seat can be metal and a stainless body is wanted. The 940 shares the body concept with seat choices of metal, nitrile, EPDM, FKM or PTFE, the 943 uses an integral metal seat, and the 950 and 953 are semi-lug cast designs rated to NPS 24 at lower pressure for larger sizes. Operators available are handwheel, bevel gear, electric, pneumatic and hydraulic, with gate guards, open and closed lockouts, limit switches, solenoid valves and fail-safe systems as options.

How the Bray Series 941 works

A flat gate slides through the valve body across the pipe line. When the gate is lowered, it cuts through the medium and seats against the metal seat to close the line. When the gate is raised, the full bore opens and the medium flows through.

Where the Series 941 is used

• Pulp and paper stock lines
• Raw and treated water
• Ash lines in power plants
• Slurry and sludge lines
• Mining process lines

Selection checklist for the Series 941

• Line size
• Medium
• Operating pressure
• Temperature
• Seat type
• Gate material
• Actuator type
• Flow direction

Installation, commissioning and maintenance notes for the Series 941

Fit the valve between line flanges using the lug holes and note the flow direction marked on the body. Cycle the valve to check the gate travel. Inspect the packing at regular intervals.

Requesting a quotation for the Bray Series 941

Please send the line size, the medium and the actuator needed. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

Series 941 valve type

It is a unidirectional knife gate valve.

Series 941 maker

It is made by Bray.

Series 941 duty

It is made for general-purpose on/off service and isolation.

Series 941 media

It suits clean, dirty, corrosive, abrasive and viscous media.

Series 941 body

The body is a single-piece lug design in CF8M stainless steel.

Series 941 dead pockets

The body has no dead pockets, so the valve drains itself.

Series 941 mounting

The lugs allow every mounting orientation, including dead-end service.

Series 941 size range

The headline range is NPS 2 to 24.

Series 941 pressure

The pressure rating is 150 psi, or 10 bar.

Series 941 flow direction

The valve seals in one direction only.

Series 941 standard seat

The standard seat is an integral metal seat.

Series 941 resilient seat

A replaceable zero-leakage resilient seat is optional.

Series 941 seat materials

Resilient seats are available in Buna-N and PTFE.

Series 941 gate edges

The gate edges are rounded to lengthen packing life.

Series 941 packing

The packing is an energized quad seal.

Series 941 anti-extrusion ring

A PTFE anti-extrusion ring is fitted as standard.

Series 941 topworks

The topworks are carbon steel.

Series 941 lubrication

Manual valves have a lubricant injection port.

Series 941 gate options

Gate options include 304, 316, duplex, Hastelloy C, Monel and titanium.

Series 941 body options

Body options include WCB, CF8, CF3M and duplex steels.

Series 941 power plant use

It is used on fly ash and bottom ash branch lines.

Series 941 food and beverage use

It is used on food and beverage storage lines.

Valve records for the Series 941

Record the line, the gate material and the date of each packing check.

Choosing the right Series 941 build

Choose the gate and seat from the medium and the temperature.

Documents and quotation

The brochure and the unidirectional knife gate operation manual are listed on the Bray page; the brochure is attached here. Confirm line medium, temperature, whether the 150 psi rating covers the required size, seat type, packing, drilling and operator before ordering.

See the wider range of control and isolation valves on our catalogue, or send the model name and order number for a quotation.