Instruments that are exposed to adverse conditions should be protected in fully enclosed and insulated boxes to avoid any kind of physical or weather damage. Even in enclosures, the instrument can still be exposed to freeze damage or if uncontrolled, overheating of the instrumentation. When the enclosure temperature is too high, fluids can vaporize or change viscosity or color. When temperatures are too low, fluids in the lines can freeze or thicken – resulting in physical damage and operation malfunction to sensitive equipment.
For many samples and instrumentation, temperature will affect measurement accuracy. The best way to solve this problem is to equip enclosures with systems designed to maintain interior temperature within the range specified for optimal performance.
The most common methods for enclosure temperature control include either steam or electricity and typically use an outside heat source to keep the enclosed equipment at an appropriately safe temperature. The risk of electrical heating can result in electrical sparks causing cable to break, jeopardizing the enclosure and equipment.
A more efficient method is steam and hot fluid tracing. In these systems a small diameter copper or stainless-steel tube is dressed around the inside of an enclosure or a coil or finned tube heating element is installed within the enclosure to supply steam. The elements from the steam main begins to circulate through the loop or heater, providing heat to protect the instruments. Steam systems can provide excellent protection, but can also result in the instrumentation overheating, if not properly controlled.
ThermOmegaTech’s self-actuating steam temperature control valves are designed to provide safe and economical control of the heating medium to automatically regulate the internal temperature of an enclosure. These self-contained, temperature activated valves simplify the control of steam flow and eliminate instrumentation overheating.
The TV/SC-I valve is installed into the wall of the enclosure so that the thermal actuator end is inside the enclosure to sense the ambient temperature. Often used for freeze protection with steam as the media, the valve monitors the internal temperature of the enclosure and automatically regulates the flow of steam to heat and maintain a set temperature.
If a design requires all connections to be within the enclosure using a steam coil to transfer heat, the TV/SC-A valve should be used. The self-actuating TV/SC-A thermostatic control valve senses enclosure temperature and allows steam flow to the coil to maintain the desired temperature inside the enclosure.
The ITCH (Instrumentation Thermostatically Controlled Heater) assembly comes complete with a steam coil, mounting brackets, TV/SC/A, two TV/HAT valves and tubing bulk-head fittings and can be mounted either internally or with an external steam supply connection. .
In reverse-acting operation, the TV/SC-IR valve is used to regulate the flow of glycol, water and other cooling media to keep the instrument enclosure cool
The TV/SC-A, TV/HAT, TV/SC-I, TV/SC-IR, and ITCH kit work as a temperature control analyzer to provide and maintain accurate temperature in an enclosure without allowing the instruments to suffer from freeze damage but also balancing the system to avoid overheating.