Atlas Copco 1202586903 Thermostatic Valve 65°C for Oil-Injected Screw Compressors

Descripción

El 1202586903 is the Atlas Copco thermostatic valve for the oil circuit of oil-injected screw compressors, listed as VALVE THERM. 65°C. The valve is the temperature-sensitive junction of the oil system: it decides how much of the oil flow passes through the oil cooler and how much takes the bypass on the way back to the element. The official part page records it under the S4B Valve rate group, with Germany as country of origin and customs tariff code 8481900090.

Oil-injected screw machines run a closed oil loop around the element, and the temperature of that loop decides how the machine behaves at part load and after a cold start. The 1202586903 holds the control at one point in the loop, working mechanically from the temperature of the oil itself, with no controller signal and no electrical part involved.

The application record for the valve is wide. It covers the stationary GA programme from the GA 75 VSD and GA 90 VSD through the GA 90 to GA 160 band and up to the GA 315 to GA 500 machines, and it reaches into the portable programme as well, from the diesel-driven XAS, XATS, XAMS, XAHS and XAVS units to the electric E-AIR T900. The parts system also records 1830080589 as the new version of the 1202586903, and both numbers are carried in the specification table below.

What the Thermostatic Valve Controls in the Oil Circuit

In an oil-injected screw compressor the oil leaves the separator, passes through the oil cooler, and returns to the element, where it lubricates the bearings, seals the compression gap and carries away the heat of compression. The loop is sized for the running temperature of the machine, but the oil does not start there: a machine that has been standing overnight holds oil at ambient temperature, and a machine running at part load makes less heat than one running fully loaded.

El 1202586903 is installed at the branch where the oil path splits between the cooler and the bypass line. While the oil is below its operating temperature, the valve keeps the flow on the bypass so the oil warms quickly in circulation. As the oil passes the rating of the valve, the element inside it shifts the flow progressively into the cooler branch, and the loop settles into its regulated temperature band.

The whole action is mechanical. Inside the 1202586903, a temperature-sensitive element reacts to the oil flowing past it and moves the internal path accordingly, so the regulation follows the machine wherever it is installed and whatever controller runs it.

The 65°C Rating and Cold-Start Protection

The 65°C in the designation of the 1202586903 is the temperature rating of the valve, the point at which its element begins to direct oil into the cooler branch. Below that point the bypass carries the flow, and above it the cooler share grows until the loop balances against the heat the machine produces.

The rating matters because oil temperature and oil condition are linked. Oil that stays below its operating temperature holds the moisture that condenses inside a compressor circuit, and that moisture travels with the oil into the bearings, the separator and the cooler. A valve that keeps the bypass path closed off until the oil is warm gives the machine a fast, clean passage from cold start to regulated running, and it is the reason oil-injected screw packages carry a thermostatic valve such as the 1202586903 as standard equipment.

For a machine that runs short duty cycles or stands in an unheated plant, the passage through that rating is where the valve does most of its work. The 1202586903 repeats the transition every start-up, which is why its condition belongs on the service list beside the filters and the separator.

Confirmed Applications Across the GA and Portable Range

The application record for the 1202586903 stretches across two sides of the Atlas Copco catalogue. The confirmed machines include:

• GA 75 VSD and GA 90 VSD
• GA 90, GA 110, GA 132 and GA 160
• GA 315, GA 355, GA 400, GA 450 and GA 500
• Diesel portable units: XAS 770, XATS 805, XATS 900E, XATS 910, XAMS 900, XAHS 805MWd, XAVS 800 and XAVS 815
• Electric portable unit: E-AIR T900

That span is worth a note. The same 1202586903 valve serves stationary plant machines and towable portable units, so a workshop that supports both sides of the fleet can carry one number for the thermostat position instead of tracking separate references per product line.

Within any of these models, build variants and market versions still differ, and the serial number is what separates them. The parts list for each serial is the record that names the thermostatic valve for that machine, and Seadweer confirms the 1202586903 against that list before an order is placed.

Especificaciones técnicas

En las tablas siguientes se recogen los datos de identificación y las características físicas registradas para el 1202586903.

Identificación de piezas

Dimensiones y peso

The figures set a light handling case. At 0.23 kg in a 10 × 5 × 5 cm package, the 1202586903 moves as a small parcel, and the valve goes from the box to the bench to the port without lifting gear or special storage. Seadweer confirms the current package details with the quotation.

When the Thermostatic Valve Needs Renewal

A thermostatic valve fails in one of two directions, and each direction shows up in the oil temperature reading. If the valve stops shifting flow into the cooler branch, the oil temperature climbs and the machine runs hot, with the cooler doing its part but receiving no oil to cool. If the valve stops holding the bypass, the oil runs cold, the machine never reaches its regulated band, and the moisture that condenses in the circuit stays in the oil.

The reading in the machine log is therefore the first check, and the valve itself is the second: an element that no longer moves, a housing full of varnish, or a stuck internal path all disqualify the unit. The 1202586903 is renewed as a complete valve, and the condition of the oil circuit around it, the cooler and the separator, is inspected in the same service window.

Plants that log oil temperature after every start-up catch the drift early. A machine that takes longer each week to reach its regulated band is describing a 1202586903 valve that is on its way out, and the log entry is what turns that observation into a planned order.

Installation and Service Planning

Renewing the 1202586903 is a short job inside a planned service stop. The machine is shut down, depressurised and isolated, the oil below the valve position is drained into a clean container, and the 1202586903 is unscrewed from its port. The sealing face is inspected, the new valve goes in with the sealing method the port was designed for, and the oil level is restored before the machine runs again.

After the restart, the oil temperature is watched through the same transition the valve controls: the reading climbs from ambient, passes the rating of the valve, and settles in the regulated band as the cooler path opens. That observed passage, recorded next to the service date and the 1202586903 number, is the baseline the next service interval starts from.

One planning note: the thermostatic valve is often replaced together with the oil and the filters in the same stop, because the circuit is already drained and the valve position is already open. Bunching the work keeps the machine out of service once instead of twice.

Ordering the 1202586903 Through Seadweer

Two pieces of information lock the order down: the number on the valve or the machine file, which reads 1202586903, and the model and serial number from the compressor nameplate. Send both to Seadweer and the parts desk confirms the thermostatic valve against the machine record, including the new version reference where the parts system lists one.

Plants that run several machines across the GA and portable ranges keep model, serial and valve number together in one record per unit. That record turns the next thermostat renewal into a single confirmed message instead of a new investigation, and it keeps the 65°C rating consistent across the fleet.

Preguntas frecuentes

Which compressors use the 1202586903 thermostatic valve?

The confirmed applications include the GA 75 VSD and GA 90 VSD, the GA 90 to GA 160 stationary band, the GA 315 to GA 500 machines, and the portable units from the XAS 770 and XATS 805 diesel machines to the electric E-AIR T900. The parts list for your machine serial number is the record that confirms the valve for that unit.

What does the 65°C marking on the valve mean?

For the 1202586903, it is the temperature rating of the valve, the point where its element begins to direct oil into the cooler branch of the circuit. Below that point the bypass carries the flow, and above it the valve shifts the oil through the cooler.

What is the 1830080589 number?

The parts system records 1830080589 as the new version of the 1202586903. The number is carried in the specification table of this page, and both references describe the thermostatic valve position in the oil circuit.

Does the valve need adjustment at installation?

No. The 1202586903 is supplied as a complete valve with its 65°C rating built in, and the temperature regulation starts working from the first start-up. The check after installation is the oil temperature reading on its way to the regulated band.

How do I know if my thermostatic valve has failed?

The oil temperature reading tells the direction: a machine that runs hot with a clean cooler, or one that never reaches its regulated band, is describing a 1202586903 valve that no longer shifts the flow. The valve is then renewed as a complete unit at the next service window.

How do I order the valve for my compressor?

Read the number on the valve or machine file, which reads 1202586903, and note the model and serial number from the compressor nameplate. Send both to Seadweer and the fitment is confirmed before the order is placed.

More Atlas Copco Valves Available

Additional Atlas Copco valves are available on request. See the table below, or contact us and we will look into your requirement.