Electric temperature control valve related introduction

It is understood that the regulating valve is used to regulate the flow, pressure and liquid level of the medium. According to the adjustment part signal, the opening of the valve is automatically controlled to achieve the adjustment of the medium flow, pressure and liquid level. The regulating valve is divided into an electric regulating valve, a pneumatic regulating valve and a hydraulic regulating valve. This manual mainly introduces two types of electric control valves and pneumatic control valves.

The regulating valve is composed of an electric actuator or a pneumatic actuator and a regulating valve. The adjustment is usually divided into two types: straight-through single-seat and straight-through two-seat. The latter has the characteristics of large circulation capacity, unbalanced operation and stable operation, so it is usually suitable for occasions with large flow, high pressure drop and low leakage. The flow capacity Cv is one of the main parameters for selecting the regulating valve. The flow capacity of the regulating valve is defined as: when the regulating valve is fully open, the pressure difference between the two ends of the valve is 0.1 MPa, and when the fluid density is 1 g/cm3, the flow path per hour The flow rate of the regulating valve is called the flow capacity, also called the flow coefficient, expressed in Cv, the unit is t/h, and the Cv value of the liquid is calculated by the following formula.

According to the table of the flow capacity Cv value, the nominal diameter DN of the regulating valve can be determined. The flow characteristic of the regulating valve is the relationship between the relative flow rate of the medium flowing through the regulating valve and its opening under the condition that the pressure difference across the valve is kept constant. The flow characteristics of the regulating valve are linear, equal percentage and parabolic. The significance of the three fluence characteristics is as follows:

(1) Equal percentage characteristic (logarithm) The relative stroke and relative flow of the equal percentage characteristic are not linear. The change of the flow caused by the change of unit stroke at each point of the stroke is proportional to the flow at this point, and the percentage of flow change It is equal. Therefore, its advantage is that the flow rate is small, the flow change is small, and when the flow rate is large, the flow rate changes greatly, that is, the same adjustment precision is obtained at different opening degrees.

(2) Linear characteristic (linear) The relative stroke of the linear characteristic is linear with respect to the relative flow. The change in flow caused by changes in unit stroke is constant. When the flow rate is large, the relative value of the flow changes little, and when the flow rate is small, the relative value of the flow changes greatly.

The flow rate varies proportionally to the two sides of the stroke and generally has an intermediate characteristic of linear and equal percentage characteristics.

It can be seen from the analysis of the above three characteristics that, in terms of its adjustment performance, the equal percentage characteristic is optimal, the regulation is stable, and the adjustment performance is good. Parabolic characteristics are better than linear characteristics, and any of the flow characteristics can be selected according to the requirements of the application.

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Label: Introduction to electric temperature control valve

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Pressure Reducing Valves

Pressure reducing valves has two types, direct operated type and pilot operated type.

Models DR are pilot operated reducing valves. They reduce pressure in a branch circuit lower than that of the main circuit. The valve design is capable of maintaining a precise pressure setting even at high flow.

Models ZDR are 3-way direct operated pressure reducing-relieving valves. They maintain a [reduced" pressure in a branch circuit and permit [relieving" pressure spike occurrences in the reduced branch circuit. Options for pressure ranges and operator adjustment options are within the scope of the modular Reducing Valve portfolio.

ZDR Features:

l  Sizes 6 and 10

l  For mounting: 
– Size 6: Porting pattern according to ISO 4401-3, NFPA T3.5.1M Ra, and ANSI B93.7 D 03 
– Size 10: Porting pattern according to ISO 4401-05, NFPA T3.5.1M R1, and ANSI B93.7 D 05

l  Pressure reduction in channel A, B or P

l  Four pressure ratings: 
– 25 bar (360 PSI), 75 bar (1100 PSI), 150 bar (2175 PSI), and 210 bar (3050 PSI)

l  Adjustment type: 
– Rotary knob

DR Features:

l  Size 10, 20

l  Nominal pressure 100, 200 Bar

l  Mounts on ISO 5781-06, 08, or 10

l  4 adjustment types for pressure adjustment, optionally:
– Rotary knob
– Hex screw with protective cap 
– Lockable rotary knob with scale
– Rotary knob with scale

Pressure Reducing Valves

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