Barksdale D1T Diaphragm Pressure Switch

Name: Barksdale D1T Diaphragm Pressure Switch – Datasheet & Quote
Brand: Barksdale
SKU: D1T

A precise NEMA 4 diaphragm switch for low-pressure and vacuum control

The Barksdale D1T is a housed diaphragm pressure switch with a terminal block wired through a 1/2 inch NPT conduit connector. A 17-7 PH stainless steel diaphragm and 304 stainless steel process fitting sit in an anodized aluminum enclosure rated NEMA 4. Barksdale quotes an accuracy of plus or minus 0.5 percent of the adjustable range, which is tighter than most compact switches, and the setpoint is set by a tamper-proof external adjustment screw.

The datasheet lists machine tools, pneumatics, medical equipment, marine and shipbuilding, pump and compressor monitoring, oil and gas, water equipment, mining and lubrication equipment. It handles both pressure and vacuum duty, and the D1T series has one switching circuit while the D2T variant in the same datasheet provides two.

Technical specifications

Parameter	Specification
Series	D1T (single circuit), D2T (dual circuit)
Switch type	SPDT snap action, single circuit (D1T)
Accuracy	+/-0.5% of the adjustable range
Contact rating	10 A at 125/250 VAC; 3 A at 480 VAC (Class A or H limit switch)
Process connection	1/4 inch NPT female
Wetted parts	304 stainless steel fitting; 17-7 PH stainless steel diaphragm
Enclosure	Anodized aluminum; NEMA 4 (NEMA 4X optional)
Electrical connection	Terminal block through 1/2 inch NPT conduit connector
Operating temperature	-40 to 165 F (-40 to 74 C); hermetic Div. 2 models -4 to 140 F (-20 to 60 C)
Storage temperature	-65 to 200 F (-54 to 93 C)
Approvals	D1T UL listed on request; D2T UL recognized component on request (file E42816); CSA listed on request (LR22355); PED compliant
Shipping weight	Approx. 2.0 lb

Range codes and proof pressure

The range code in the part number selects the adjustable window. Choose a code that puts the trip point in the middle of the range and keep system peaks below the proof pressure. The pressure ranges as printed:

Range code	Decreasing setpoint (psi / bar)	Increasing setpoint (psi / bar)	Approx. deadband	Proof pressure
2SS	0.018 to 1.65 (0.0 to 0.1)	0.068 to 1.7 (0.0 to 0.1)	0.02 to 0.05 psi	3 psi (0.2 bar)
3SS	0.03 to 2.85 (0.00 to 0.2)	0.18 to 3 (0.02 to 0.2)	0.07 to 0.15 psi	10 psi (0.7 bar)
18SS	0.4 to 17.74 (0.03 to 1.2)	0.66 to 18 (0.05 to 1.2)	0.12 to 0.26 psi	60 psi (4.1 bar)
80SS	0.5 to 76.6 (0.03 to 5.3)	3.9 to 80 (0.3 to 5.5)	1.6 to 3.4 psi	160 psi (10.9 bar)
150SS	1.5 to 144 (0.1 to 9.9)	7.5 to 150 (0.5 to 10.3)	2.3 to 6 psi	300 psi (20.4 bar)

Two vacuum ranges are also listed: 3SS adjusts 0.06 to 5.72 in. Hg decreasing and 0.34 to 6 in. Hg increasing, and 18SS adjusts 0.8 to 29.2 in. Hg decreasing and 1.6 to 30 in. Hg increasing. Deadband values apply with the standard H limit switch.

Ordering code, options and limit switches

The datasheet example is D1T -A 80SS -U. The limit switch letter selects the contact: A is 10 A at 125/250 VAC and 3 A at 480 VAC (standard on 3SS, 80SS and 150SS); H has the same rating and is standard on 2SS and 18SS; C is rated 10 A at 125/250/480 VAC with 2 A at 600 VAC; M adds 0.5 A at 125 VDC; GH is a gold-contact type for 1 A at 125 VAC or 24 VDC; CC and HH are hermetically sealed for Class I Division 2 (10 A and 5 A at 125/250 VAC), not available on 2SS or vacuum models. Options include -U UL approved, -CS CSA approved, -Z13 oxygen cleaned, -FX NEMA 4X enclosure, -TC temperature stabilisation and pre-cycle, -L6 six-pin terminal block (D2T only) and -Sxxx factory preset.

Installation and checks: the process connection is 1/4 inch NPT female. For pressure service, turning the adjustment screw counterclockwise raises the actuation point; for vacuum, turning it clockwise raises the setpoint. Operating temperature is -40 to 165 F (-40 to 74 C), or -4 to 140 F (-20 to 60 C) on hermetic Division 2 models, and shipping weight is about 2 lb. Confirm the media against 17-7 PH and 304 stainless steel, the proof pressure against your peaks, whether UL or CSA marking is required (D1T can be ordered UL listed, D2T as a UL recognized component, CSA on request) and the contact rating for your load. The datasheet states PED compliance.

Documents and quotation

The attached file is the two-page Barksdale datasheet for the D1T and D2T series (bulletin S0062-J). Other switches are in pressure instrumentation. Send the full code with limit switch, range and options for a quotation.

Pressure, level and temperature switches

The Barksdale range covers compact and diaphragm pressure switches, electronic switches with optional IO-Link, float and electronic level switches, tank level transmitters, temperature switches and pressure transducers. Typical uses are hydraulic power units, compressors, lube and fuel skids, engines, cooling circuits and tanks.

Frequently Asked Questions