Do thermostatic traps have a check function?

In thermostatic traps, the bimetal disc type and the diaphragm cartridge type have a one-way valve function, but the bellows type should not have it.

Here are some of the well-known brands recognized in the valve industry, which are widely recognized and have a high reputation. While rankings may vary depending on time and market conditions, the following brands are generally considered to be among the top brands in the valve industry:

The following influential first-line brands of water system valves and industrial valves can be used as a reference, but for reference only: Suzhou Neway Valve, Shanghai Guanlong Valve, Shanghai Qizhong Valve, Sanhua, Su Yan, Shentong, Su Valve, Nanfang, Jiang.

First, the word Yao. The above manufacturers are only estimates and references, and the specific situation may vary or fluctuate at any time due to changes in a series of factors such as changes in the market, the size of the competition pattern, and the stability of product quality. As an indispensable key device in industrial production and civil facilities, the quality and reputation of the valve brand directly affect the satisfaction and trust of users.

These brands are known in the valve industry for their innovative technology, high-quality products and reliability. It is important to note that the market and industry are evolving rapidly, and different rankings may vary depending on time and region. For the most up-to-date ranking information, it is recommended to refer to industry reports, professional organizations or market research data for more detailed and accurate information.

Thermostatic traps play a role in the steam heating system to block steam drainage, and choosing the right trap can make the steam heating equipment achieve the highest working efficiency. In order to achieve the best results, it is necessary to have a comprehensive understanding of the working performance and characteristics of various types of traps.

There are many types of traps, each with different properties. When choosing a trap, you should first choose its characteristics to meet the optimal operation of the steam heating equipment, and then consider other objective conditions, so that the choice of the trap you need is correct and effective.

Traps need to be able to "identify" steam and condensate in order to act as a steam barrier drain. The "identification" of steam and condensate is based on three principles: density difference, temperature difference, and phase transition.

Therefore, three types of traps are manufactured according to three principles: mechanical, thermostatic, and thermodynamic.

Traps are mainly used for condensate drainage in steam pipes, and they are able to drain water without venting. Save energy.

This type of trap uses the temperature difference between steam and condensate to cause the deformation or expansion of the temperature sensing element to drive the valve core to open and close the valve. The supercooling degree of thermostatic trap is relatively large, generally the subcooling degree is 15 degrees to 40 degrees, it can use part of the sensible heat in the condensate, there is always high temperature condensate in front of the valve, no steam leakage, and the energy saving effect is remarkable. It is the most ideal trap in steam pipelines, heat tracing pipelines, small heating equipment, heating equipment, and small heating equipment with low temperature requirements.

The main action element of the diaphragm box trap is the metal diaphragm, which is filled with a liquid whose gasification temperature is lower than the saturation temperature of water, and there are two options for opening the valve with a temperature lower than the saturation temperature of 15 and 30. The diaphragm trap is particularly responsive, not afraid of freezing, small in size, resistant to overheating, and can be installed in any position. The back pressure rate is greater than 80%, it can discharge non-condensable gas, the diaphragm box is firm, the service life is long, the maintenance is convenient, and the use range is very wide.

When the device is just started, the pipeline is condensed at a low temperature, the liquid in the diaphragm box is in a condensed state, and the valve is in the open position. When the temperature of the condensate gradually increases, the filling of the membrane begins to evaporate, the pressure in the membrane rises, the diaphragm drives the valve center to move in the direction of closing, and the trap begins to close before the condensate reaches the saturation temperature. The diaphragm box controls the valve switch with the change of steam temperature, which plays the role of blocking steam and drainage.

The spool of a bellows trap is filled with a liquid that vaporizes at a temperature lower than the saturation temperature of water. With the change of steam temperature control valve switch, the valve is equipped with adjustment bolts, can adjust the use temperature according to the need, the general subcooling adjustment range is lower than the saturation temperature 15 -40. The back pressure rate is greater than 70%, not afraid of freezing, small size, can be installed in any position, can discharge non-condensable gas, and has a long service life.

When the device is started, the pipeline appears to cool condensate, the liquid in the bellows is in a condensed state, and the valve core is in the open position under the elastic force of the spring. When the temperature of the condensate gradually increases, the liquid filling in the bellows begins to evaporate and expand, the internal pressure increases, the deformation elongates, and the valve core moves in the direction of closing. The main component of the bimetal trap is the bimetal disc temperature sensing element, which is heated and deformed with the rise and fall of steam temperature, and pushes the valve core to open and close the valve.

The bimetal disc trap is equipped with adjustment bolts, which can adjust the operating temperature according to the need, the general subcooling adjustment range is lower than the saturation temperature of 15 -30, the back pressure rate is greater than 70%, it can discharge non-condensable gas, it is not afraid of freezing, it is small in size, it can resist water hammer, it can withstand high pressure, and it can be installed in any position. Bimetal sheets are fatigued and need to be adjusted frequently.

When the device is just started, the pipe has a low temperature condensation, the bimetal sheet is flattened, the valve core is in the spring elastic force, and the valve is in the open position. As the condensate temperature rises, the bimetal disc temperature sensing element begins to bend and deform, pushing the valve core to the closed position. Before the condensate reaches saturation temperature, the trap begins to close.

The bimetal sheet controls the valve switch with the change of steam temperature to block steam and drain water.

During the start-up phase, the disc is jacked up due to pressure and condensate and air are discharged through the inner valve seat through the lower part of the disc through the three small holes at the peripheral outlet (see diagram showing only 2 small holes).

Thermodynamic traps have a movable valve plate that is both a sensitive and actuator. According to the different thermodynamic principles of the flow rate and volume change when steam and condensate pass through, different pressure differences are generated between the upper and lower parts of the valve plate, and the valve plate is driven to open and close the valve. The steam leakage rate is 3%, and the subcooling degree is 8 -15.

A thermodynamic trap is a very robust trap with a simple way of working. The trap works by the power generated by flash steam passing through the trap, and as shown in Figure 1, the only moving part is a disc located on a flat surface in the control chamber.

According to the principle of phase change, this type of trap relies on the different thermodynamic principles of flow velocity and volume changes when steam and condensate pass through, so that different pressure differences between the upper and lower parts of the valve plate are generated, and the valve plate is driven to open and close the valve. Because the thermodynamic trap does not have the working power of the wide valve, the steam waste is relatively large. The structure is simple, water hammer resistant, the maximum back is 50%, there is noise, the valve plate works frequently, and the service life is short.

Thermodynamic trap trap type has thermodynamic type (disc type), pulse type, orifice plate type Orifice trap is based on different displacement, select orifice plates with different pore sizes to control the displacement. The structure is simple, and if the selection is not suitable, there will be insufficient drainage or a large amount of steam, and it is not suitable for intermittent production of steam-using equipment or steam-using equipment with large fluctuations in condensate volume.

Thermostatic traps, disc traps are used in steam pipe networks and equipment, can automatically discharge condensate, air and other non-condensable gases, and prevent water and steam leakage.

According to the different working principles of traps, traps can be divided into the following types: This type of valve should generally be installed horizontally in the pipeline.

1. Mechanical type: It depends on the change of the condensate level height in the thermostatic trap, including:

Float type: The float is a closed hollow sphere.

Open upward float type: The float is a barrel type with an open upward opening.

Open downward float type: The float is a barrel type with an open downward opening.

2. Thermostatic type: It depends on the change of liquid temperature and acts, including:

Bimetal: Sensitive components are bimetallic.

Vapor pressure type: The sensitive element is a bellows or ink cartridge, and the inside is filled with volatile liquid.

3. Thermodynamic type: It depends on the change of the thermodynamic properties of the liquid.

Disc type: due to the different flow rates of liquid and gas under the same pressure, different dynamic and static pressures are generated, which drives the disc valve plate to act.

Pulse type: Because the condensate of different temperatures passes through the two poles in series with the orifice plate, the different pressures between the two pole orifice plates drive the valve disc to act.