Changing the Temperature Sensing Unit on Heated Hose

EL-51A-4-2TThe equipment used today for spraying plural component urethane foam and coatings provide the means to preheat the A and R chemicals, pressurize the chemical to the manufacturer’s recommended PSI and deliver that conditioned and heated chemical to the gun via a heated hose. Most units today utilize a system which provides automatic hose heat. The proportioners are equipped with a controller which receives a signal from a temperature sensing unit. The signal indicates the temperature of the chemical in the hose from a remote distance from the proportioner and ideally just before the gun.

These sensing units are better known as TSU, FTS or RTD. These sensing units are installed on the hose and in most cases are very close to the gun. Since the hoses are dragged over obstacles, dropped and go through rough use, the sensing units will break and must be replaced. Some equipment manufacturers provide a sensing unit that is one piece and requires that all the hoses be disconnected to replace the unit. This is time consuming, costly and messy. PMC offers a Slim Line TSU housing that allows for the thermocouple to be replaced WITHOUT removing the hoses. When replacing a PMC thermocouple it is recommended that you place the TSU on a bucket as shown below, which will prevent chemical from leaking on the floor.

  1. Bleed down the pressure on your system
  2. Unplug the TC or RTD harness
  3. Remove the old Thermocouple and insert a replacement
  4. Tighten the fitting, reconnect the harness, bleed the system and you are ready to spray.

Replace TSU by PMC

Founded in 2007 on the principle of “designed with the customer in mind”, PMC targets engineers with a complete product line for urethane spray systems including but not limited to proportioning units, a uniquely designed heated hose system, transfer pumps, spray guns and the auxiliary equipment required by a contractor to successfully and economically apply residential foam insulation, roofing, pour foam, Polyurea and Polyurea hybrid coatings. Manufactured in the USA, all of PMC’s products are the direct result of customer input, innovation, creativity and the perfectionist spirit of its engineers. PMC’s full line of equipment is available at

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SprayWorks Equipment Group is a spray foam and polyurea company; supplying equipment, training, material, mobile rigs, and parts – and a distributor for PMC, Graco, and Gusmer equipment. With nearly 100 years of combined experience, SprayWorks has knowledge in commercial and residential buildings, bridges, and infrastructure. SprayWorks provides training and education for new contractors and equipment operators; open cell, closed cell, polyurea & coating applications for interior & exterior building envelope design, waterproofing, below grade, bridge deck, barge, secondary containment all types of roofs and structures.