NOSHOK 1000 Series Piston Differential Pressure Gauge

A magnetic-piston differential pressure gauge for filters and heat exchangers

The NOSHOK 1000 Series is a compact piston-type differential pressure gauge. Pressure applied to both ports moves a ceramic piston and magnet inside a clear anodized aluminum or 316 stainless steel sensor housing, and a magnetic movement turns the pointer, so there is no mechanical link through the pressure boundary. Ranges run from 0-5 psid to 0-110 psid, and the gauge comes in 2-1/2, 4-1/2 and 6 inch sizes with an engineered plastic case.

Maximum working static pressure is 3,000 psig with the aluminum housing and 6,000 psig with 316 stainless steel. Optional single or dual SPDT switches, or a 4-20 mA transmitter in a NEMA 4X IP65 plastic enclosure, add remote alarms.

1000 Series specification

Dimensions from the datasheet:

Order code explained

Example: 25-10 1 2 – P5 – A 2 P – 1 means 2-1/2 inch 1000 series, back connection (1), 1/4 inch NPT female (2), 0-5 psid (P5), aluminum sensor housing (A), FKM o-ring (2), engineered plastic case (P) and shatter-resistant acrylic lens (1).

Selection notes

• Choose stainless steel for aggressive media or above 3,000 psig static pressure.
• Pick a range around two times the expected normal differential so the clogging alarm point sits mid-scale.
• A maximum indicating pointer is available on dry 2-1/2 and 4-1/2 inch gauges only.
• Fill (glycerin or silicone) is for vibration; silicone fill has restrictions on the 4-1/2 inch size, as the datasheet footnote explains.

Applications in Oman and the GCC

Filter monitoring on lube oil and seal oil skids, cooling water strainers, heat exchanger fouling checks, flow indication across orifice plates and level indication in tanks are listed uses. In the GCC the piston design copes with wide temperature swings from -40 F to 200 F. Check the O-ring against your fluid: NBR is standard, FKM and PTFE suit more aggressive media.

How to size the range and housing

A differential gauge reads the difference between two line pressures, but both ports see the full line pressure, so the housing rating is a static limit, not the differential range. In a lube oil filter on a 10 bar header, a 0-30 psid gauge will see that static pressure on both sides; an aluminum housing at 3,000 psig is ample, while a 400 bar hydraulic system needs the 316L stainless version at 6,000 psig. A filter that changes at 25 psid suits a 0-50 psid range; at P25 the pointer would be at full scale at the change-out point. The switch option is adjustable between 15 and 95 percent of range and is rated SPDT 3 W, 0.25 A at 125 V, which is a small signal rating, so use a relay for larger loads. The reversed ports option swaps high and low sides for installation.

Selection and installation notes

A pressure instrument is selected from the pressure range, the process media and the connection. Choose a range so that the normal operating pressure lies in the middle of the scale, check that the wetted materials suit the fluid, use the correct seal and thread, fit an isolation valve or snubber where pulsation or surges occur and mount the instrument where it can be read and serviced. Never exceed the overpressure limit on the data sheet, and keep a record of calibration.

A differential gauge reads the pressure drop across a filter or heat exchanger, so connect the high and low ports to the correct sides and use isolation valves.

Information needed for a quotation

Send the full model code, the quantity, the delivery location in Oman or the GCC, the intended use and any accessories needed, so that the complete package can be quoted together.

Documents and supply information

The manufacturer data sheet is attached to this page and should be read together with the project specification and the site risk assessment before a purchase is confirmed. Ratings, standards and dimensions are quoted as printed on that sheet. Lead time, stock position and certificates available with the shipment are confirmed in the quotation, and we supply to Oman and the wider GCC region for industrial, utility and building services projects.

Related items and documents

See also the NOSHOK 400/500 stainless pressure gauge and our pressure instrumentation category. The datasheet is attached; Seven Star LLC can quote against your range, size and switch requirement.