Seat Options for Butterfly Valves
ters-accessories-seat-options-for-butterfly-valves
BUNA-N is the commonly used name for Nitrile synthetic rubber. Nitrile is a copolymer of acrylonitrile and butadiene. BUNA-N is sometimes referred to as NBR, Nitrile, or Hycar. BUNA-N is an excellent general purpose seat material which is particularly suitable for hydrocarbon service. BUNA-N is a standard Bray seat material and is Food Grade; thus suitable for sanitary applications. Note, BUNA-N is also available as a covering for Series 20 disc stems. Bray Resilient Seats.jpg
FKM is the ASTM D1418 designation for Fluorinated Hydrocarbon Elastomers (Fluoroelastomers) such as Viton® (DuPont). FKM has some outstanding characteristics such as improved acid, oil, and temperature resistance over standard seat materials. Bray Resilient Seats.jpg
Urethane seats are primarily used for their ability to resist abrasive wear. Urethane can be used on a reasonably broad range of services. Urethane will withstand severe impact, recover its original shape after distortion and resist abrasion better than other elastomers such as EPDM and BUNA-N. Bray Resilient Seats.jpg
PTFE lined EPDM seat consists of a PTFE liner which forms the faces and the flow way of the seat, and is molded on to an EPDM elastomer backing. Only the inert non-stick PTFE liner surface is exposed to the line media. The EPDM backing acts as a resilient support to the relatively rigid PTFE. These seats are generally used where BUNA-N and EPDM seats are not chemically suitable, especially in corrosive services Bray Resilient Seats.jpg
PTFE lined EPDM seat consists of a PTFE liner which forms the faces and the flow way of the seat, and is molded on to an EPDM elastomer backing. Only the inert non-stick PTFE liner surface is exposed to the line media. The EPDM backing acts as a resilient support to the relatively rigid PTFE. These seats are generally used where BUNA-N and EPDM seats are not chemically suitable, especially in corrosive services Bray Resilient Seats.jpg
All Bray PTFE seats and encapsulated discs are molded from pure, virgin PTFE material to the following specifications: thickness 3 mm, specific gravity 2.16, crystallinity 68%. PTFE’s inherent molecular bonding strength gives an excellent chemical, high temperature and tear resistance. Sintered processed PTFE offers lower permeability than melt processed materials such as PFA. These properties combined with Bray’s stringent material specifications provide optimum protection against permeation of the line media. Bray Resilient Seats.jpg
Bray Conductive PTFE seats and discs are available for installation in areas of the plant where explosion protection is important. This material was designed to prevent harmful electrostatic discharge. For the ultimate in safety and reliability, Bray has combined electrostatic discharge protection and the excellent chemical resistance properties of PTFE. The conductive PTFE seat and the disc has a minimum thickness of 1/8” (3 mm), providing optimum protection against permeation of the line media. Bray Resilient Seats.jpg
UHMWPE seats and discs feature exceptional chemical resistance and are the ideal choice for highly abrasive chemical applications. The natural ability of the UHMWPE’s high molecular weight to repel solids prevents in-line particles from damaging the valve’s seat surfaces. An economical and high performance choice for abrasive chemical services. Bray Resilient Seats.jpg
EPDM (Peroxide Cured) Seats for Butterfly Valves
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EPDM is the abbreviated name for Ethylene Propylene Diene Monomer. In general industry, one may see other abbreviations or trade names used in lieu of EPDM such as EPT, Nordel, ECD, or EPR. Typically these are the same materials as EPDM.
EPDM is a standard seat material offered in Bray resilient-seated butterfly valves. It is the most universal and economical of seat materials offered by Bray; that is, it may be used in a wider range of applications than BUNA-N. Of important significance also is the fact all EPDM seat materials sold by Bray are Food Grade. Bray’s EPDM Food Grade seats are perfectly suitable for sanitary applications as well as standard industrial uses. EPDM is also available as a covering for Series 20 discs.
BUENA-N (Black & White) Seats for Butterfly Valves
BUNA-N is the commonly used name for Nitrile synthetic rubber. Nitrile is a copolymer of acrylonitrile and butadiene. BUNA-N is sometimes referred to as NBR, Nitrile, or Hycar. BUNA-N is an excellent general purpose seat material which is particularly suitable for hydrocarbon service. BUNA-N is a standard Bray seat material and is Food Grade; thus suitable for sanitary applications. Note, BUNA-N is also available as a covering for Series 20 disc stems. Bray Resilient Seats.jpg
FKM Seats for Butterfly Valves
FKM is the ASTM D1418 designation for Fluorinated Hydrocarbon Elastomers (Fluoroelastomers) such as Viton® (DuPont). FKM has some outstanding characteristics such as improved acid, oil, and temperature resistance over standard seat materials. Bray Resilient Seats.jpg
Polyurethane Seats for Butterfly Valves
Urethane seats are primarily used for their ability to resist abrasive wear. Urethane can be used on a reasonably broad range of services. Urethane will withstand severe impact, recover its original shape after distortion and resist abrasion better than other elastomers such as EPDM and BUNA-N. Bray Resilient Seats.jpg
PTFE Lined EDPM (Standard) Seats for Butterfly Valves
PTFE lined EPDM seat consists of a PTFE liner which forms the faces and the flow way of the seat, and is molded on to an EPDM elastomer backing. Only the inert non-stick PTFE liner surface is exposed to the line media. The EPDM backing acts as a resilient support to the relatively rigid PTFE. These seats are generally used where BUNA-N and EPDM seats are not chemically suitable, especially in corrosive services Bray Resilient Seats.jpg
PTFE Lined EDPM (High-Temp) Seats for Butterfly Valves
PTFE lined EPDM seat consists of a PTFE liner which forms the faces and the flow way of the seat, and is molded on to an EPDM elastomer backing. Only the inert non-stick PTFE liner surface is exposed to the line media. The EPDM backing acts as a resilient support to the relatively rigid PTFE. These seats are generally used where BUNA-N and EPDM seats are not chemically suitable, especially in corrosive services Bray Resilient Seats.jpg
Virgin PTFE Seats for Butterfly Valves
All Bray PTFE seats and encapsulated discs are molded from pure, virgin PTFE material to the following specifications: thickness 3 mm, specific gravity 2.16, crystallinity 68%. PTFE’s inherent molecular bonding strength gives an excellent chemical, high temperature and tear resistance. Sintered processed PTFE offers lower permeability than melt processed materials such as PFA. These properties combined with Bray’s stringent material specifications provide optimum protection against permeation of the line media. Bray Resilient Seats.jpg
Conductive PTFE Seats for Butterfly Valves
Bray Conductive PTFE seats and discs are available for installation in areas of the plant where explosion protection is important. This material was designed to prevent harmful electrostatic discharge. For the ultimate in safety and reliability, Bray has combined electrostatic discharge protection and the excellent chemical resistance properties of PTFE. The conductive PTFE seat and the disc has a minimum thickness of 1/8” (3 mm), providing optimum protection against permeation of the line media. Bray Resilient Seats.jpg
UHMWPE Seats for Butterfly Valves
UHMWPE seats and discs feature exceptional chemical resistance and are the ideal choice for highly abrasive chemical applications. The natural ability of the UHMWPE’s high molecular weight to repel solids prevents in-line particles from damaging the valve’s seat surfaces. An economical and high performance choice for abrasive chemical services. Bray Resilient Seats.jpg
