ZMA/BP-16D pneumatic thin film straight through low-temperature single seat regulating valve and ZMAN-16D pneumatic thin film straight through low-temperature double seat regulating valve are two types of pneumatic actuators. It has been widely used in the automatic control of industrial production processes such as petroleum, chemical, and metallurgical industries. It is particularly suitable for controlling and regulating media (such as liquid oxygen and liquid nitrogen) at low temperatures ranging from -60 ℃ to -250 ℃. To ensure adjustment accuracy, a valve positioner must be used.

Structural characteristics:
1. Pneumatic low-temperature regulating valve is a variant product of pneumatic straight through single or double seat regulating valve. The difference is that in order to ensure the normal operation of the valve at low temperatures ranging from -60 ℃ to -250 ℃, a long neck (extension cover) has been added to the upper valve cover to keep the packing working at room temperature.
2. Pneumatic low-temperature regulating valves are divided into two types according to their operating modes: gas closed and gas open. For low-temperature single seat valves, when the nominal diameter DN is less than 25mm, the ZMA type pneumatic diaphragm actuator is used for the air closing type due to the single guide valve core; The pneumatic opening adopts ZMB type pneumatic thin film actuator. When the nominal diameter is ≥ 25mm, due to the dual guidance of the valve core, ZMA type pneumatic thin film actuators are used for both the air closing and air opening types. When converting from an air closing type to an air opening type, simply screw the valve stem on the other end guided by the valve core, flip the valve body up and down 180 °, and switch the positions of the upper and lower valve covers.
3. The material of the pneumatic low-temperature regulating valve (see Table 5) and the length of the long neck (dimension H1 in Figure 2) should be selected reasonably at different working temperatures.
4. The pneumatic low-temperature regulating valve is equipped with screw holes on both sides of the bracket of the pneumatic actuator for installing the handwheel mechanism and valve positioner.