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B-Series pressure and vacuum switches use two different actuators depending on setpoint requirements. For setpoints
between 2 and 3000 psi, the simple, rugged diaphragm-sealed piston actuator is used. This design features high
reliability and choice of actuator seal materials for virtually every application. An optional welded design is also
available for setpoints up to 1000 psi for maximum reliability. This design is available in 316 SS or Monel.
For setpoints between 4.5 and 150 inches of H2O, a large diaphragm is used for increased sensitivity with good
choice of materials of construction.
Erläu ter ung, z usätz lic h ei n Hi n weis:
6.3.2 Process adapter of pressure switch D7
Differential pressure models use a unique, dual diaphragm-sealed piston design that features very high static
operating pressures and small size.
For setpoints between 1.5 and 150 inches of H2O, a large diaphragm is used for increased sensitivity with good
choice of materials of construction.
6.3.3 Process adapter of temperature switch T7
B-Series temperature switches feature a SAMA Class II vapor pressure thermal system. This system provides quick,
accurate response to process temperature changes with negligible ambient temperature effects. This is inherent in the
design due to the precise relationship that exists between temperature and pressure according to the vapor pressure
laws. A wide selection of sensing bulb and armored capillary lengths is available. The vapor pressure system design
features small bulb sizes, making installation easy and cost-effective.
6.3.4 Set point adjustment
A single setpoint adjustment nut (7/8”) is located centrally at the bottom on the inside of the enclosure.
6.3.5 Micro switch
Standard electrical switch is SPDT, available with various electrical characteristics. Two SPDT switch elements
mounted together are available except on variable Deadband and manual reset types.
Microswitch Code Electrical rating
Single Dual VAC VDC
20 61 15 A, 250 V 0,4 A, 120 V
21 65 5 A, 250 V
22 67 5 A, 250 V 2,5 A, 28 V
23 22 A, 250 V
24 64 15 A, 480 V 0,25 A, 250 V
25 10 A, 250 V 10 A, 250 V
26 62 15 A, 250 V 0,4 A, 120 V
27 63 15 A, 250 V
28 15 A, 250 V
29 15 A, 250 V
31 70 1 A, 250 V 50 mA, 60 V
32 68 11 A, 250V 5 A, 30 V
42 71 1 A, 125 V
50 15 A, 250 V
35 10 A, 250 V 0,3 A, 250 V
Table 1: Micro switch electrical ratings
6.3.6 Enclosure
The Ashcroft snap action pressure switch is furnished in the flameproof NEMA 7 & 9 and ATEX Ex db and dust ignition
protected ATEX Ex tb enclosure styles. Enclosure is epoxy coated aluminum casting or optional stainless steel 316L.
6.4 Accessories
Please contact the manufacturer regarding special tools and accessories.
7 Transport
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