How do mixer valves work

It is important that a boiler's high temperature limits do not exceed the maximum temperature rating of the system components. This will protect against component temperature failure should dirt, sediment, or other mechanical failure cause a mixing valve to become inoperable. Regular inspection of mixing valves is recommended to assure maximum valve life and a properly functioning system.

Corrosive water conditions, unauthorized adjustments or repairs can be detected during inspection and service of the valve.

The frequency of cleaning depends upon local water conditions. Heat Traps All mixing valves used at the source of supply should be trapped. Trapping the valve helps reduce mineral deposits and premature component wear. Heat traps help reduce convection loss also know as thermosiphoning, increasing system efficiency. When utilizing a mixing valve for this purpose, some of the hot supply water mixes with cooler water returning from the distribution system, the blend is directed back to the boiler.

The objective is to boost the boiler inlet temperature high enough to prevent flue gas condensation, which usually means above 55C F. This return water boosting is never required for a condensing boiler, and with more and more condensing boilers being installed today, this is not an application that will be seen very often anymore.

Two temperature hydronic system with thermostatic mixing valve. There are three main technologies used for thermostatic mixing valves: wax element technology, bi-metal strip, and liquid filled technology.

The most common type seen in residential and small commercial applications, for both plumbing and heating, is the wax element technology. The wax element provides high accuracy, fast response and extremely long life, with few moving parts. A thermostatic mixing valve utilizes three major components for its operation: some sort of spindle or shaft, a thermal element and a return spring. The return spring provides an upward return force to the thermal element.

The thermal element acts as a movable unit, which reacts to changes in temperature, opening ports to change the water flowing between the hot and cold water inlets. When tempered water is in use, the thermal element senses the outlet temperature and positions a seat assembly, which controls the flow of hot and cold water supplied to the mixed water port.

If the mixed outlet temperature increases, the thermostat will expand, moving the seat assembly to allow more cold water in and at the same time restricting the hot water inlet port.

Conversely, if the mixed outlet temperature decreases, the thermostat will contract, allowing the more hot water in and restricting the cold water inlet port. In both cases the mixed outlet water temperature is automatically and continually maintained at the pre-set temperature. Most valves will have a safety feature which shuts off the hot or cold inlet port in the event of a cold or hot water supply failure.

The valve will have a mechanical adjustment in the form of a dial or set screw at the top, which permits the user to select the desired outlet water temperature within range of the valve.

This will have to be set up at the time of system commissioning and is much easier do if a temperature gauge is installed in the mixed water line downstream of the valve. Some valves on the market are available with a built in thermometer to make set up very easy.

Internal view of a thermostatic mixing valve. So the answer is clear: thermostatic mixing valves are essential for both plumbing and hydronic heating. Make sure you use them properly to protect your customers and protect their floor systems, while providing optimum performance from the hot water supply and the heating system. Exact matches only. Search in title. Search in content. Search in excerpt.

View Digital Edition Digital Archives. Thermostatic mixing valves: Applications in plumbing and hydronic heating May 30, By Robert Waters. Hydronics Plumbing Sponsored. Residential thermostatic mixing valve.

Print this page Tweet. Bradley customizes offerings for industrial applications. A radiant winner for Cooper Plumbing and Heating. Sponsored content. I agree We are using cookies to give you the best experience on our website. By continuing to use the site, you agree to the use of cookies. Of course, Markets comprises of various types of valves that can set the temperature between C. There has been many physical as well as mental effects seen in the children and elder people due to high temperature set in Thermostatic Mixing Valves.

The elderly when exposed to high temperature in Thermostatic Mixing Valves have been found to have prolonged hospitalization. In case of children the exposing of high temperatures results in lifelong scalds along with traumatic experience.

TMVs are made to counter the change determined by the temperature which is verified by the various TMV arrangements. It safe guards approved products by providing water in anti-scald temperature spectrum. Third party testing conducts it and confirms. Whenever a user suddenly changes water temperature directly from cold to hot, it results in temporary increase of seven degree Celsius. It then supplies water at a high temperature than the prescribed maximum. Therefore, users are not advised to make sudden changes in temperature control while using shower.

If the main pressure and the pressure from water with high temperature differs then the water with high temperature is forced back. The high temperature water then goes down the pipe through a one sided valve which blocks the other side. This results in failure of maintaining the water temperature desired by the user.

However, an open vented system localizes expansion from the water heater. So, the contamination and a result of bad plumbing or incorrect plumbing can cause the failure in temperature control system. Proper installation and maintenance are also important in order to protect the filtration measures.

The checking on the product are also needed for correct performance. Initial phase is the most important phase in every case. Sometimes the flow of regulators are stopped or jammed. It is due to the damp winter season which causes this sort of trouble.

This will often show up in winter season so servicing within weeks of commissioning is necessary. While installing it is necessary to check the manuals and instructions that come with the package. Alternatively, you can find more information in our privacy policy. Thermostatic Mixing Valves Guide. Mechanism of Thermostatic Mixing Valves The mechanism of Thermostatic Mixing Valves is a basic wax thermostatic principle which limits the quantity of hot water and cold water by blending.

There are four components that make up a Thermostatic Mixing Valve. These four components are: Thermostatic element These thermostatic elements are the temperature sensitive elements which contracts and expand in relation to the water temperature. Return Spring Return Spring is the component in thermostatic mixing valve that functions by pushing the piston back to its normal position after the contraction or expansion of the piston due to the change in water temperature.

Temperature Adjuster This adjuster as name denotes is kept under the shield lock of the valve and has the ability to adjust the temperature in the valve. Temperature limitations for the Thermostatic Mixing Valve Muilding regulations for domestic property has clearly mentioned that the normal new households or materially changed households bathroom should not exceed maximum temperature of 48 C.