How to select your Amot temperature control valve

   Checklist:

  • Flow Rate

  • Actuation Method

  • Flow Configuration

  • Body Material

  • Seal Material​

  • Elements

  • Special Features

The Selection Guide​

Since AMOT offers such a large selection of different sizes, actuation methods, body materials, and customized features, selecting the right valve for your application requires careful consideration of how the valve will be used and the environment in which it will be installed.

Flow Rate (GPM)

One of the first things to consider is your required flow rate, as this will determine the valve size. If you know your flow rate, the chart below will help narrow down the choices. Note: these values are for water; heavier fluids will lower the maximum range.

Actuation Method​

 

It is important to consider your application requirements and business goals when deciding if you

need a thermostatic control valve or actuated control valve.

Self-actuated valves

  • “Fit and Forget Solution”

  • One preset temperature setting

  • Standard control range (+/- 3-5°F)

  • Self-contained; no extra parts needed

  • Fully mechanical

Externally-actuated valves 

“Performance Improvement Solution”

  • Flexible temperature adjustment

  • Precise temperature control (+/-1°F)

  • Complete system: controller, temperature sensor, etc.

  • Requires electric or pneumatic activation source

Amot-Valve-Actuation-Method.jpg

Flow Configuration

 

Our temperature control valves work equally well in both mixing and diverting applications, as illustrated in the drawings below.

Mixing Applications

When valves are used for mixing service, Port C is the cold fluid inlet port from the cooler, Port B is the hot by-pass fluid inlet, and Port A the common outlet. Port A is the temperature sensing port and will mix the hot and cold fluids in the correct proportion to produce the desired outlet temperature leaving Port A.

Diverting Applications

When valves are used for diverting services, the inlet is Port A (temperature sensing port), with Port C being connected to the cooler, and Port B connected to the cooler by-pass line.

Body Material

Different body materials work best in different applications.

• Cast Iron: General use for most water, glycol, and oil systems

• Ductile Iron: High strength at lower cost than steel; best for marine applications

• Steel: High strength, high pressure rating

• Stainless Steel: Highest corrosion resistance, high strength, high pressure rating

• Bronze: Best for salt water and Navy applications

• Aluminum: For low cost, high pressure service

Amot-seals-buna-viton-neoprene.png

Seal Material

Buna seals are standard, and work best for petroleum-based oils, water, and glycol.

 

AMOT offers alternative seal materials for applications where Buna is not compatible with the working fluid.

 

  • Viton: High temperature and synthetic oils

  • Neoprene: Refrigeration applications using ammonia or freon

Elements

Standard bronze and steel elements work well in almost all applications. However, if your application contains corrosive fluids, such as ammonia or salt water, we recommend electroless nickel plated elements for protection.

Amot-elements.jpg

Elements

Standard bronze and steel elements work well in almost all applications. However, if your application contains corrosive fluids, such as ammonia or salt water, we recommend electroless nickel plated elements for protection.

Amot-elements.jpg

Leak Holes

Leak holes are drilled to allow a small flow of fluids for the following reasons:

  • To allow small flows to cooler during start up which slows down warm up cycle

  • To allow small flows to maintain some flow through cooler in order to prevent condensation or in extreme cases freezing - in cases where additives are not or cannot be used

  • In applications where valve is used as a 2-way valve. With port "B" blocked, when curcuit is cold and port closed, leakhole is necessary to ensure small flow in order for element to sense temperature change, allowing the unit to function

Amot-manual-override.JPG

Manual Override

BR-series valves are provided with a manual override that allows a progressive opening of the valve. Manual override is often a requirement for marine applications. In automatic mode the valve will control the temperature automatically, but turning the adjusting nut on top of the valve wil cause the element to move towards its cold (extended) position, regardless of temperature. There is a position indicator on each manual override which shows the element position during manual operation. Each thermostat assembly has its own manual override. 

The manual override should only be used in case of an emergency, or thermostat failure. 

All G-model valves have a manual override built into the actuator assembly. 

Special Features

The last thing to consider is whether any special features are required by your applications.

This can include:

 

• Element leak holes

• Manual override

• Nonstandard end connections

• Industry certifications

Ing. Westad AS

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