Samson Series 43 Self-Operated Temperature Regulators

Samson Series 43 self-operated temperature regulators for heating and cooling

The Samson Series 43 is a family of temperature regulators that work without any electric or pneumatic auxiliary energy. A thermostat with a temperature sensor opens or closes a small globe or three-way valve according to the temperature of a heat-exchanger outlet, a tank or a process line. The overview datasheet T 2170 covers valve sizes DN 15 to 50 (NPS ½ and 1 in the ANSI versions), pressure ratings PN 16 and PN 25 or Class 150 and 300, connections G ½ to 1 or ½ to 1 NPT, and temperatures up to 200 °C (390 °F). Seven Star LLC supplies Series 43 regulators in Oman and the GCC as an independent supplier in Muscat.

These regulators are proportional devices: the sensor liquid or vapour changes volume with temperature and the resulting force moves the plug. Because they need no power, they are valued for remote skids, heat tracing headers, lube-oil coolers and steam heaters where a failing power supply must not cause overheating.

Series 43 type designations

The datasheet lists a range of types, each designed for a certain medium and duty. The type number is therefore the main ordering key, followed by the valve size and the thermostat range.

Check the individual type datasheets (T 2171 to T 2178) for which of these combinations applies to your medium; the overview table groups many characteristics in columns, and the right choice must be confirmed by the manufacturer data for the exact type.

Series 43 technical specifications

How the regulator works

The temperature sensor, capillary tube and operating element are connected as a closed system. When the sensor warms up, the expansion of its filling moves the operating element and the plug stem, so the valve closes (or opens in a cooling type) in proportion to the temperature rise. The set point is set on the thermostat and read off a dial. The speed of response is dominated by the sensor, which is why the datasheet lists time constants with and without a thermowell and why the choice of thermowell has a direct effect on control quality.

Where the Series 43 fits in a plant

A combined double adapter (Do3) can be placed between valve and thermostat to add a safety temperature limiter (Type 2439 STL) or a second thermostat; the Type 2403 safety thermostat is used for a safety temperature monitor (STM) and the Type 2439 limiter can include an electric signal transmitter for remote alarm. Combinations with flow and differential pressure regulators are also possible. The related Samson Type 2040 STM and the Type 46-6 and Type 47-5 regulators are separate pages on this site.

Selection checklist for a Series 43

• Controlled medium (steam, water, oil, gas) and whether heating or cooling is required.
• Required set point range and the thermostat range that contains it with margin.
• Mixing or diverting function or a straight globe valve.
• DN, KVS and the differential pressure available at the valve.
• Body material, pressure rating and temperature limit including the 80 °C limit for gases.
• Thermowell material and length and the need for a safety limiter or monitor.
• DIN or ANSI version, and end connections.

Installation, commissioning and maintenance of the Series 43

Mount the valve with the flow arrow respected, put the sensor where the medium is well mixed and fully immersed, and run the capillary tube away from heat sources. Protect the sensor with a thermowell when the process cannot be drained for sensor replacement. After commissioning, check the closing temperature against the thermostat dial, and note that the regulator is proportional, so a small offset from the set point will remain under load. Maintenance is limited to cleaning strainers, checking seat leakage and inspecting packing.

Typical applications of Series 43 in Oman and the GCC

Common uses are oil coolers on compressors and pumps, heating of fuel and heavy oil lines, steam heaters for process tanks, water heaters at camps and plant buildings, and temperature holding of chemical injection skids. In hot ambient conditions the cooling versions help keep lubricants within limits without relying on instrument power.

Information to send with your Series 43 RFQ

• Medium, flow, inlet and outlet temperature and the required set point.
• Operating pressure and differential pressure at the valve.
• Heating or cooling duty; mixing or diverting function.
• DN, connection type and DIN or ANSI standard.
• Thermowell and capillary length requirement.
• Any safety temperature monitor or limiter needed.
• Quantity and delivery site.

Documents and quotation

The Samson overview data sheet T 2170 for Series 43 is attached on this page. Send your duty data and the type you prefer, and we will confirm available documents, availability and lead time. Seven Star LLC is an independent supplier and does not claim any official status with the manufacturer.