Bray Series 755 Urethane-Lined Bidirectional Knife Gate Valve

Replaceable polyurethane liner for abrasive slurry service

The Bray Series 755 is a bidirectional knife gate valve with a field-replaceable polyurethane bore liner, offered as an economical answer for abrasive applications. It uses the same steel-reinforced perimeter seat as the Series 752, mechanically retained between the two halves of a two-piece bolted wafer body, which gives bidirectional zero-leakage shutoff. The size range is NPS 2 to 24 (DN 50 to 600) at 240 psi (16 bar).

An optional polyurethane liner bonded to both halves of the body, designated 755P, protects the body completely from the media. Because the body bolts apart, the seat and liner can be changed in the field instead of replacing the whole valve, and that maintenance story is the main reason to specify a 755 over a one-piece lug valve on tailings, sand and mineral lines.

Technical specifications

Source: Bray brochure EN_Bro_S755 dated 2025-09-01. Bray notes the dimension table applies to 10 to 16 bar; consult the factory for 20 bar.

Weights and operators by size

Operators are a direct-mounted handwheel as standard for NPS 2 to 10, a bevel gear as standard for NPS 12 to 24, and pneumatic, hydraulic or electric actuators on request. Approximate weights printed by Bray show how quickly the package grows with size, which matters for pipe support design.

Choosing the lined 755 against other slurry valves

The 755 sits between the unlined 752, which has the same seat and body concept, and the sleeved SlurryShield valves, where twin rubber sleeves and a push-through gate seal around the gate. The 755 suits abrasive media that do not need a fully shielded flow path. If the slurry is heavy, hot or pressurized beyond this range, step to the 762, 767 or 768 series, and if the application is a standard clean-water isolation a lug valve such as the 740 is usually enough.

How the Bray Series 755 works

The Series 755 is a knife gate valve. A flat gate slides up and down between two halves of the body. When it is lowered, it cuts through thick or solid-laden media and closes against a seat. The steel-reinforced perimeter seat is held between the two halves of the body, and the seal works in both flow directions. The optional polyurethane liner covers the bore and protects the body from abrasive slurry.

Where the Bray Series 755 is used

• Mining tailings and mineral lines
• Sand and gravel slurries
• Wastewater and sludge
• Pulp and paper stock
• Bulk handling of dry solids

Selection checklist for the Series 755

• Size from NPS 2 to 24, DN 50 to 600
• Pressure rating of 240 psi, 16 bar
• Body: WCB, CF8 or CF8M
• Gate: 304 or higher alloys such as duplex
• Seat: Buna-N, EPDM or Viton
• Liner option 755P with polyurethane
• Operator: handwheel, bevel gear or an actuator
• Drilling to ASME B16.5 Class 150

Installation, commissioning and maintenance notes

Fit the valve between flanges with the pipe supported, since the weight grows quickly with size. Check the actuator and its supply. Operate the gate through a full cycle and watch for leaks at the packing. In service, adjust or replace the packing as needed and, because the body bolts apart, change the seat and the liner in the field when they wear.

Requesting a quotation for the Bray Series 755

Please send the size, the media, the pressure, the liner option and the operator type. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

Series 755 seat materials

Buna-N serves from -37 to 90 degrees C, EPDM from -54 to 120 degrees C and Viton from -26 to 200 degrees C.

Series 755 standards

The design follows MSS SP-81, the testing follows MSS SP-151, and the valve carries a Canadian CRN.

Series 755 operators

A handwheel is standard for NPS 2 to 10 and a bevel gear for NPS 12 to 24, with pneumatic, hydraulic or electric actuators on request.

Series 755 weights

A DN 50 valve with a handwheel weighs about 17 kg and a DN 200 valve about 63 kg.

Valve records for Series 755

Keep the tag, the seat material and the dates of liner or seat changes with the plant file.

Choosing the right Series 755 liner

Choose the 755P liner where the slurry is abrasive and the body must be protected.

Series 755 body and gate options

The standard body is WCB with a 304 gate and 304 stem, PTFE-impregnated synthetic fibre packing and steel topworks. Body options include CF8 and CF8M, and gate options include 316, 317, SAF 2507 and 2205 duplex, 17-4PH, Hastelloy C and Monel.

Series 755 pressure versions

The main rating is 240 psi, 16 bar, and the Bray guide also lists versions at 150 psi, 10 bar, and 300 psi, 20 bar.

Documents and quotation

The brochure is attached; the page lists no other 755 documents. Please confirm media, particle size and abrasiveness, temperature, pressure, seat and gate material and operator type before requesting a quotation, and check whether the 150, 240 or 300 psi construction is needed.

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