Question 1

What is a temperature control valve and how does it work?

Accepted Answer

A temperature control valve is a self-actuated or pilot-operated valve that automatically regulates the flow of a heating or cooling medium to maintain a desired process temperature at a specific point. Self-actuated (thermostatic) temperature control valves use a temperature-sensing element (liquid-filled bulb, wax element, or bimetallic sensor) that expands or contracts in response to temperature changes. This expansion directly moves the valve plug toward open or closed to increase or decrease the flow of the heating or cooling medium, maintaining the temperature at the setpoint without any external power source or control system. Pilot-operated temperature control valves use a temperature sensor to control a small pilot valve, which in turn controls the main valve — this arrangement provides greater force and capacity for larger valves and higher-pressure applications. Centro carries the TV/US-X steam heat tracing control valve, which monitors and controls the flow of heating media in steam heat tracing systems that protect piping and equipment from freezing and maintain process temperatures.

Question 2

What is steam heat tracing and why are temperature control valves needed?

Accepted Answer

Steam heat tracing is a method of maintaining or raising the temperature of pipes, tanks, and process equipment by running small-bore steam supply tubing (called tracer tubes) alongside or wrapped around the piping or equipment being heated. The steam in the tracer tubes provides heat to prevent the process fluid from freezing, crystallizing, becoming too viscous to flow, or dropping below a required process temperature. Temperature control valves are needed in steam heat tracing systems to regulate the amount of steam flowing through the tracer tubes to maintain the desired temperature without overheating. Without a temperature control valve, the full steam supply pressure and temperature would constantly heat the traced piping, potentially overheating temperature-sensitive products, wasting steam and energy, and causing excessive condensate that can lead to water hammer. The TV/US-X temperature control valve available through Centro monitors the traced pipe or equipment temperature and automatically modulates the steam flow to maintain the setpoint — opening to increase heating when temperature drops and closing to reduce heating when the setpoint is reached.

Question 3

What industries and applications use temperature control valves?

Accepted Answer

Temperature control valves are used wherever process temperature must be maintained automatically. Chemical and petrochemical plants use them extensively for steam heat tracing of process piping to prevent crystallization, solidification, or viscosity increases in chemicals that become difficult or impossible to pump if they cool below a critical temperature. Refineries use them to maintain crude oil, fuel oil, asphalt, and other petroleum products at flowable temperatures. Food and beverage processing uses them to maintain product temperatures during transport and storage, and to control heating and cooling in process tanks and heat exchangers. Pharmaceutical manufacturing uses them for precise temperature control of reactors, jacketed vessels, and product piping. Power plants use them for steam system temperature regulation, feedwater heating control, and freeze protection. HVAC systems use them for hot water and chilled water temperature control at heating and cooling coils. Pipeline systems use them for freeze protection of instrumentation, sampling systems, and process piping in cold climates.

Question 4

What is the advantage of a self-actuated temperature control valve over an electronic control loop?

Accepted Answer

A self-actuated temperature control valve operates entirely on the thermal energy from the process — it requires no electrical power, no compressed air, no control wiring, no PLC or DCS programming, and no electronic temperature transmitter. This makes it ideal for remote locations where utilities and control infrastructure are not available or practical, for simple temperature control applications where the cost and complexity of an electronic control loop is not justified, and for installations where intrinsic safety is a priority (no electrical components in hazardous areas). Self-actuated valves are also inherently reliable because they have no electronic components that can fail, no software that can crash, and no communication links that can be lost. They provide continuous, proportional control (not just on/off switching) with response times appropriate for the thermal lag of most heat tracing and process heating applications. However, self-actuated valves cannot be remotely monitored, adjusted, or integrated into a plant-wide control system — for applications requiring centralized monitoring, remote setpoint changes, or data logging, an electronic control loop with a motorized or pneumatically actuated control valve is the better choice.

Question 5

How do I select a temperature control valve for a steam heat tracing system?

Accepted Answer

Selecting a temperature control valve for steam heat tracing requires matching several parameters. Determine the temperature setpoint range needed — the valve's sensing element must be capable of controlling within the required temperature range for the specific process. Determine the steam supply pressure and the condensate backpressure to ensure the valve is rated for the differential pressure across it. Size the valve to handle the steam flow rate required by the heat tracing circuit — this depends on the heat loss of the traced piping (which is a function of pipe size, insulation type and thickness, ambient temperature, and wind exposure) and the steam conditions. Select the appropriate sensor type and location — the temperature sensing element (bulb or capillary) must be mounted in good thermal contact with the pipe or equipment being traced, and positioned where it accurately represents the temperature being controlled. Verify that the valve body and trim materials are suitable for the steam conditions (pressure, temperature) and any condensate chemistry issues. For the TV/US-X valve available through Centro, consult with Centro's product specialists to match the valve model and trim to your specific steam pressure, temperature range, and heat tracing circuit requirements.

Temperature Control Valves

$974.51$1,006.00

$360.36$372.00

$420.42$434.00

$420.42$434.00

$360.36$372.00

$1,273.62$1,314.77

$1,198.06$1,236.77

$583.91$602.77

$643.96$664.77

$732.12$755.77

$1,198.06$1,236.77

$583.91$602.77

$643.96$664.77

$583.91$602.77

$732.12$755.77

$583.91$602.77

$1,273.62$1,314.77

$1,273.62$1,314.77

$583.91$602.77

$643.96$664.77

$583.91$602.77

$643.96$664.77

$420.42$434.00

$360.36$372.00

$974.51$1,006.00

$360.36$372.00

$420.42$434.00

$420.42$434.00

$360.36$372.00

$1,273.62$1,314.77

$1,198.06$1,236.77

$583.91$602.77

$643.96$664.77

$732.12$755.77

$1,198.06$1,236.77

$583.91$602.77

$643.96$664.77

$583.91$602.77

$732.12$755.77

$583.91$602.77

$1,273.62$1,314.77

$1,273.62$1,314.77

$583.91$602.77

$643.96$664.77

$583.91$602.77

$643.96$664.77

$420.42$434.00

$360.36$372.00

Orders & purchases

Divisions