Multi-spring Pneumatic Diaphragm Actuator

Multi-spring Pneumatic Diaphragm Actuator is a new pneumatic diaphragm actuator, which is designed and developed for the problems of the old ZMA/B single–spring pneumatic diaphragm actuator, such as large size, bulky, reliable deep corrugated diaphragm, etc. The shape of the diaphragm is relatively complex, and special pressing technology is adopted to make the blasting intensity reach more than 2kg/cm². Multi–spring form improves the spring manufacturing process, and it is advantageous to the different spring range combination. Zeroing improves linearity. Surface treatment with high fastness and corrosion resistance, and adopts epoxy electrostatic powder spraying.

It has the advantages of uniform force, good stability, small size and light weight. Besides, it can be equipped with pneumatic, electric valve positioner and air filter accessories. It can also be equipped with ZPXS, ZDXS type light side mount, and top mount manual operation mechanism.

Actuator

Item	ZJHA/B-11	ZJHA/B-22	ZJHA/B-23	ZJHA/B-34	ZJHA/B-45	ZJHA/B-56
Rated Stroke (mm)	10	10, 16	16, 25	40	40, 60	100
Active Area (cm²)	200	350	350	560	960	1600
Size of Air Connection	M16×1.5	M16×1.5	M16×1.5	M16×1.5	M16×1.5	M16×1.5
Air Pressure	colspan=6 0.14, 0.25 MPa
Ambient Temperature	colspan=6 -30 ~ +6 °C
Spring Range	colspan=6 20–100 KPa, 40–200 KPa, 80–240 KPa
Action	colspan=6 ZJHA: Direct action — stem moves down when signal pressure increases. ZJHB: Reverse action — stem moves up when signal pressure increases.

Application Data

1. Flow Characteristics

This product mainly has two kinds of inherent flow characteristics to choose from: straight line and equal percentage. Because of careful design and manufacturing, the accurate flow characteristics of the product are guaranteed, which is in line with the requirements of IEC standard slope method assessment, so as to promote the use of high quality control effect. This flow characteristic is designed according to the adjustable ratio R50. Compared with the product of R30, it expands the possibility of single valve to realize wide load change control and it is more suitable for most systems with low pressure drop ratio between valve and system.

2. Relationship between Working Pressure and Temperature

When selecting the nominal pressure of the control valve in terms of the maximum nominal pressure of the process medium, we must meet the requirements of the medium working temperature. Because the nominal pressure is set according to the strength condition at a certain reference temperature. Once the operating temperature exceeds the reference temperature, the maximum allowable working pressure must be lower than the nominal pressure. Please pay more attention about this point above.

3. Allowable Pressure Difference

When selecting the control valve, in addition to other conditions, we should also consider the thrust angle, that is to say, whether the control valve can operate normally, and whether it can be expressed with characteristic data, which means the allowable pressure difference is higher than the maximum working pressure difference.

In order to improve the degree of standardization, applicability and serialization, the actuator parts and valve parts in the control valve have a set of standard combinations. The allowable differential pressure specified in various combinations can usually be applied to the working differential pressure conditions in general process.