Ashcroft T4/T7 Temperature Switch

Fits local temperature switching on process duties that need a gas-actuated thermal system (direct stem or remote bulb/capillary) with SPDT or dual snap-acting contacts in a NEMA 4X or explosion-proof NEMA 7/9 enclosure.

Key advantages

−40…750 °F family — Setpoint ranges from −40…60 °F through 500…750 °F.
Direct or remote — Gas-actuated stem or remote bulb/capillary (5…25 ft).
SPDT / dual snap — Single or 2×SPDT acting as DPDT microswitch elements.
T4 or T7 enclosure — NEMA 4X/IP66 (T4) or NEMA 7/9/IP66 explosion-proof (T7).
SIL3 listed family — UL, CSA, CE, SIL3, ATEX/IECEx options on T7 codes.

Typical applications

Local high/low temperature switching on process vessels and lines.
Remote-bulb installs where the switch head must sit away from the process.
Hazardous-area temperature switching needing NEMA 7/9 / Ex d options.

Selection guide

Setpoint range — Ranges from −40…60 °F through 500…750 °F (−40…750 °F family span). Pick the range that covers set/reset, not just process max.
Sensor — Gas-actuated thermal system (direct-mount stem or remote bulb/capillary).
Repeatability — Setpoint repeatability ±1% of span (additional ±1% of range per 50 °F from initial setpoint at 70 °F typical).
Switch element — SPDT or 2×SPDT acting as DPDT snap-acting microswitch; ratings element-code dependent.
Process connection — Direct mount ½ NPT Male; remote mount ½ NPT Male bushing (XBX opt.).
Stem / capillary — Direct stem 2¾″…24″; remote capillary 5…25 ft (5 ft increments).
Sheath — Direct: 316 SS; Remote: 316 SS bulb/capillary; spiral armor 302 SS.
Enclosure — T4: NEMA 4X, IP66; T7: NEMA 7/9, IP66. Epoxy-coated aluminum; optional 316 SS (explosion-proof styles).
Electrical — ¾ NPT Female conduit (std); optional ½ NPT Female, M20×1.5.
Area classification — T7: Class I Div 1 Groups B,C,D / Class II Div 1 E,F,G; ATEX/IECEx Ex d IIC T6 (with XCN etc.).

Common mistakes

Picking a range from process max only — lock the setpoint range that covers set and reset.
Ordering T4 when the area needs T7 NEMA 7/9 / Ex d — enclosure is a model choice.
Leaving stem length or capillary length blank (direct 2¾″…24″; remote 5…25 ft).
Expecting a powered transmitter output — this is a snap-acting temperature switch.
Claiming SIL3 / ATEX without the matching T7 / XCN order codes on the quote.

When to RFQ / what to tell us

T4 vs T7, setpoint range, set/reset direction, and SPDT vs dual contacts.
Direct stem length or remote capillary length; process connection.
Required area marks, conduit entry, quantity, ship-to.

Request a Quote · Get selection help

Specs

Spec	Value
SKU	37261
Brand	Ashcroft
Model	T4/T7 (B-Series) Temperature Switch
Product type	switch
Measuring / setpoint range	Setpoint ranges from −40…60 °F through 500…750 °F (−40…750 °F family span)
Sensor type	Gas-actuated thermal system (direct-mount stem or remote bulb/capillary)
Accuracy / repeatability	Setpoint repeatability ±1% of span (additional ±1% of range per 50 °F from initial setpoint at 70 °F typical)
Output signal	SPDT or 2×SPDT acting as DPDT snap-acting microswitch
Supply	Switch-element dependent (AC/DC ratings per element code; not a powered transmitter)
Process connection	Direct mount ½ NPT Male; remote mount ½ NPT Male bushing (XBX opt.)
Stem / probe length	Direct mount stem lengths 2¾″…24″
Sheath material	Direct: 316 SS; Remote: 316 SS bulb/capillary; spiral armor 302 SS
Housing material	Epoxy-coated aluminum (watertight); optional 316 SS (explosion-proof styles)
IP rating	T4: NEMA 4X, IP66; T7: NEMA 7/9, IP66
Electrical connection	¾ NPT Female conduit (std); optional ½ NPT Female, M20×1.5
Approvals	UL; CSA; CE; SIL3; ATEX; IECEx
Hazardous area	T7: Class I Div 1 Groups B,C,D / Class II Div 1 E,F,G; ATEX/IECEx Ex d IIC T6 (with XCN etc.)
Mounting	Direct or remote reading thermal systems; capillary 5…25 ft (5 ft increments)
Notes	Pipeline title “B Series Temperature Switch” maps to current OEM T4/T7 datasheet (B-D-T safety/SIL family). Ambient temperature blank on extract used — confirm on quote.

Documents

FAQ

Q: T4 or T7 — which enclosure do I need? A: T4 is NEMA 4X / IP66 (watertight). T7 is NEMA 7/9 / IP66 for Class I Div 1 / Class II Div 1 service (and ATEX/IECEx Ex d options). Match the area classification in the RFQ.

Q: Direct stem or remote bulb? A: Direct mount for local head-at-process; remote bulb/capillary (5…25 ft) when the switch head must sit away from heat or vibration. Stem lengths 2¾″…24″ for direct mount.

Q: Is this a transmitter? A: No. It is a snap-acting temperature switch (SPDT or 2×SPDT). Electrical ratings follow the switch-element code — state load voltage/current in the RFQ.

Q: What should I send for a quote? A: Set points, range, direct vs remote, stem/capillary length, switch element, T4 vs T7, required marks, quantity. Compatible with systems using Ashcroft T4/T7 if you need a drop-in check — we do not claim authorized-dealer status.