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Reotemp’s Threaded Flow Thru Diaphragm Seal is ideal for installation in applications requiring little interruption to process flow. The W540 is available in threaded connections up to 2” NPT.

Construction Materials

Diaphragm: 316SS, Hast C-276, Tantalum, Monel, or others
Lower Housing: 316SS, Hast C-276, Monel, or others
Gasket: PTFE, Grafoil, or Klinger
Upper Housing: 316SS Standard

Process Temperature Limits

Metallic Lower Limit (°F)
PTFE Gasket -110/350°
Klinger Gasket -110/450°
Grafoil Gasket -40/600°
EPDM 300°
Natural Rubber 212°

Ambient Temperature Limits

Determined by the Pressure Instrument

Minimum Recommended Span

2.5” & 3.5” Gauges 15 psi
4”, 4.5”, & 6” Gauges 30 psi
Transmitter (Gauge Pressure) 150” H2O
Transmitter (Differential Pressure) 300” H2O
Differential Pressure Gauge (D40/42 Only) N/A

Maximum Working Pressure at 100°F

Bolts Grade 5 Grade 8 18/8SS 316SS
Metallic Lower W540 2,500 psi 2,500 psi 1,500 psi 1,500 psi


Metallic Lower: 4.5lbs.