Description
PTFE Diaphragm Normally Closed, Air to Open
Process Connection Size
1 1/2"
Body Material
PVC
Seal Material
PTFE
Connection Type
Threaded
Max Pressure at 40 - 75 Degrees F
6.8
Max Inlet Pressure (PSI)
100
Max Inlet Pressure (Bar)
6,90
Max Back Pressure (PSI)
25
Max Back Pressure (Bar)
1,72
Cv
17
Orifice Size
1.5
Air Inlet Connection
1/8"
Fail Dry
Yes
Air-Operated Shut-off Valves with PTFE Diaphragm
Series BSDA/BSDAM
Compact valves for corrosive and ultra-pure liquids
in Geon® PVC, Corzan® CPVC, PTFE, Kynar® PVDF & Natural Polypropylene
¼" through 1½" sizes
Features
- Compact size with PTFE diaphragm construction.
- No metal in contact with liquid.
- Various end connections available.
- Million cycle non-sticking design.
- Various body materials available:
Geon® PVC, Corzan® CPVC, PTFE, Kynar® PVDF, Natural unpigmented Polypropylene. - Normally closed design
("fail-safe" spring to close; air to open). - Patented Fail-Dry® vented design.
- Inlet pressures to 100 PSI ---
(see table below for complete specifications.)
Designed for pressure and drain applications processing ultra pure water and highly corrosive chemicals. The valve is ideal for a wide range of uses, from pharmaceutical to semiconductor in PTFE, Kynar PVDF or Polypro body materials; car washes to chemical plants in the lower-cost Geon PVC body materials, and higher temperatures in those applications with Corzan CPVC bodies.
For high purity applications such as deionized water, Series BSDA/BSDAM provides the ultimate in non-leaching, contamination-free sealing. The standard valves are air pressure to open, with "fail safe" spring return to close. Because the diaphragm is attached to the piston, no inlet pressure is required to assist with opening. The BSDA/BSDAM is not designed for vacuum service.
Discontinued Series BSD was an earlier design with a non-attached diaphragm. Series BSDA and former Series BSD are identical in all other respects. Series BSDA supersedes Series BSD.
New Series BSDAM is a molded body with molded integral mounting lugs and an optional gauge port. Series BSDA and BSDAM are identical in all other respects.
Diaphragm Design
The standard diaphragm material is PTFE for the ultimate in purity, backed with FKM for the ultimate in strength and flexibility. The FKM side is not in contact with liquid.
Materials of Construction
Wetted body materials available standard are Geon® PVC, Corzan® CPVC, PTFE, Kynar® PVDF, and Natural Unpigmented Polypropylene. Other body materials and custom materials may be available, depending on costs and/or quantity.
Compact air cylinder head standard material is Geon PVC, regardless of the body material. Seals used for cylinder are Buna-N. Spring is steel; fasteners are stainless steel. None of these materials contact liquid. If for some reason these are not acceptable for your application, other air section materials can be provided depending on costs and/or quantity. We urge you to contact our Technical Group at (973) 256-3000 to discuss your application.
Operation
A 3-way air solenoid valve connected to the 1/8" NPT port on the air cylinder head is required to actuate the diaphragm valve. When air pressure (40 to 100 psi) is applied, the diaphragm valve opens. Consult the table below for complete air specifications. When the air pressure is vented away through the 3-way air solenoid valve, the internal spring automatically closes the diaphragm. (This is referred to as "normally-closed, air-to-open/spring return valve). The spring is not in contact with liquid. It is recommended that filtered, lubricated compressed air be used.
The cylinder head features multiple seals, in addition to the main diaphragm seal in contact with the liquid. There is a vent located between two seals (above the main diaphragm, below the cylinder head u-cups) that will "weep" in the event of a primary seal failure. The valve will still function, under pressure, without metal contacting liquid. This is the patented Plast-O-Matic Fail-Dry®, which adds an additional layer of "protection" for your process.
Piping Connections
The standard valves are precision machined from the highest quality brand thermoplastic bar stock with female NPT connections. 1/2" sizes in Geon PVC, Corzan CPVC, Natural Polypro & Kynar PVDF are molded with a choice of FNPT or socket connections. Spigot connections & flare fittings (shown at right in PP) are also available on all sizes. For orders of 25 or more valves, connections can be provided with male threads, sockets, unions, etc. Please consult our Technical Group for more information, (973)256-3000.
Mounting
1/2" and 1" sizes in PVC, CPVC, Natural Polypro & Kynar PVDF have integral mounting lugs on the base of the body, as shown at right. This is in addition to mounting holes in the base. These sizes and materials can be ordered optionally without the mounting lugs if desired.
All other sizes & materials have threaded mounting holes in the base.
Gauge Ports & Fail Dry Port
1/2" size in PVC, CPVC, Natural Polypro & Kynar PVDF have opposing 1/8" NPT gauge ports on the side of the body, on the same plane as the piping connections, as shown at right. 1" size in PVC, CPVC, Natural Polypro & Kynar PVDF have opposing 1/4" NPT gauge ports on the side of the body, on the same plane as the piping connections, as shown at right. The gauge ports are not tapped unless so ordered; incurs small charge. On the standard body, the untapped port has no effect on flow or performance. Gauge ports are not readily available on other size/material combinations; please consult factory for alternatives.
The threaded port above the piping connection is the patented Fail-Dry early warning vent. Fail-Dry is standard on all sizes and materials.
Applications
Series BSDA/BSDAM PTFE diaphragm valves have been used successfully in Semiconductor fabs, pharmaceutical processing, deionized water, chemical processing, potable water treatment, chemical injection systems, battery filling, wastewater treatment, dialysis systems, and many other applications since it was introduced in 1984. This is a proven design for high purity processes, providing 1,000,000 cycles in normal use.
Series BSDA in Kynar PVDF shown with optional spigot connections