Ashcroft EI Bimetal Thermometer with Everyangle Connection

Overview

The Ashcroft EI is an external-adjust bimetal thermometer with a hermetically sealed stainless steel case, offered in 2, 3 and 5 inch dial sizes. The sealed case prevents the entry of moisture, interior corrosion and coil freeze-up, and the silicone-dampened bimetal coil reduces pointer flutter on vibrating equipment while improving response. Ashcroft lists offshore oil rigs, chemical and petrochemical plants, refineries, power, water and wastewater, pulp and paper, HVAC, equipment skids, pharmaceutical and biotech, and food and beverage among its typical uses.

Seven Star LLC supplies the Ashcroft EI to process plants, HVAC contractors, OEMs and maintenance teams in Oman and across the GCC, with engineering support in Muscat. For buyers searching for a thermometer supplier in Oman, the Ashcroft EI is a dependable choice where a rotating dial and a field-adjustable reading are required.

Measuring Principle

As general engineering background, a bimetal thermometer relies on a helical coil formed from two bonded metal strips with different thermal expansion. When the stem is heated, the coil winds or unwinds and turns a shaft connected directly to the pointer, so the instrument needs no power, wiring or transmitter. In the Ashcroft EI the coil is dampened with silicone, which steadies the pointer on pumps, compressors and skids and, according to Ashcroft, also improves response time.

Ashcroft describes the EI as its external adjust bimetal, and the external adjustment allows quick and limited span adjustments in the field without opening the case. Ashcroft states that the Ashcroft EI is satisfactory for continuous service up to 425 °C and can be used intermittently from 425 to 500 °C. Overtemperature limits depend on range: up to 100% of span for ranges topping out at 250 °F, 50% for ranges between 251 and 550 °F, and 800 °F maximum for ranges between 551 and 1,000 °F.

Engineering Design of the Ashcroft EI

The case and stem are all-welded 304 or 316 stainless steel, and the Maxivision® dial with black figures on white minimises parallax reading errors. The window can be glass, acrylic or safety glass. On 3 and 5 inch models the connection can be Everyangle™, lower or rear; the Everyangle™ dial rotates 360° so it can be turned to face the operator after the stem is installed, while the 2 inch model uses a rear connection.

Process connections include plain stem, pointed stem (2 inch), fixed ½ NPT (¼ NPT on 2 inch), ½ NPT union and ½ NPT adjustable union, the last allowing both rotation and adjustment of the insertion depth. Stem diameters are 0.250 in, with 0.375 in as an option, and stem lengths run from 2½ to 60 in, with standard lengths of 2½, 4, 6, 9, 12, 15, 18 and 24 in. Protection is NEMA 4X/IP66, ambient temperature limits are −40 to 93 °C, and Ashcroft backs the instrument with a 5-year limited warranty.

Key Features

The Ashcroft EI offers these practical benefits.

• Hermetically sealed case prevents moisture ingress, interior corrosion and coil freeze-up.
• Accuracy of ±1% of span per ASME B40.200 (B40.3 grade A).
• Silicone-dampened coil reduces pointer flutter in high-vibration applications.
• Everyangle™ connection lets the dial rotate 360° for easy reading.
• External adjustment allows quick, limited span adjustments in the field.
• Maxivision® dial minimises parallax errors, with customised dial printing and dual scale options.
• All-welded 304 or 316 stainless steel construction rated NEMA 4X/IP66.
• Stem lengths from 2½ to 60 in and diameters of 0.250 or 0.375 in fit most thermowells.

Industrial Applications

In Oman the Ashcroft EI is used on chilled water supply and return headers in district cooling plants and commercial buildings, on hot water and steam condensate lines, lube oil coolers on compressors and generators, process lines in refineries and petrochemical plants at Sohar and Duqm, and offshore and coastal installations where a sealed stainless case resists salt air. Food, beverage and pharmaceutical plants in the Rusayl and Sohar industrial estates also specify it where a hermetically sealed instrument is required.

Ashcroft advises that thermowells be used on all pressurised applications above 15 psi, to protect the thermometer from corrosion or physical damage and to allow removal without disturbing the process. For a WIKA alternative, the WIKA A52 Bimetal Thermometer, Back Mount, Stainless Steel Case serves similar HVAC duty, and a WIKA TR10 RTD Sensor can be added where the temperature must reach a control system; the Ashcroft 1279 Duragauge Pressure Gauge is a natural pressure companion on the same skid. Seven Star LLC supplies the Ashcroft EI with engineering support across Oman and the GCC.

Technical Specifications

The Ashcroft EI data below is taken from the Ashcroft EI Bimetal Thermometer data sheet.

Ordering Example

The datasheet gives 30EI 60 R 060 XSG 0/200°F as an example: a 3 inch dial, fixed ½ NPT connection, rear location, 6 inch stem, safety glass window and a 0 to 200 °F range. When ordering an Ashcroft EI for an existing thermowell, measure the well depth and thread so we can choose the stem length that places the coil in the flow.

As general guidance on range selection, pick a scale whose normal operating temperature falls in the middle of the dial, because bimetal coils are most accurate and least stressed there. A chilled water header running at 6 to 12 °C, for example, is usually fitted with a −10/50 °C range, while a hot water return at 60 to 80 °C suits a 0/120 °C dial. Dual Celsius and Fahrenheit scales are useful on imported equipment whose documentation is in imperial units.

How to Order

Request a quotation for the Ashcroft EI from Seven Star LLC with the dial size, connection type and location, stem length and diameter, range, window and any options such as dual scale or a calibration certificate. Our Muscat team will confirm availability and lead time, supply the Ashcroft data sheet and support temperature measurement needs across Oman and the GCC.