□ APPLICATION AREA The multi-spring membrane pneumatic actuators of P/R type are applied for control operation of control valves, and other positioning elements in industrial automatic systems. There are three following design options of the actuator: – Direct action (air – advances the steam) – Reverse action (air – retracts the steam) – Direct action, handwheel – Reverse action, handwheel
□ FEATURES ! Completely reversible action, option to change spring range w/o extra parts. ! Rigid structure of cast yoke. ! Wide range of the available forces. ! Linear relationship between rod displacement and control pressure as a result of using membranes with constant active area. ! Various ranges of spring pressures due to changeability of spring number and /or dislocation of distance fencers. ! Capability of the actuator to incorporate side-mounted handwheel, pneumatic or electro-pneumatic positioners, limit switches, air sets, three-way pneumatic solenoid valves, lockup valves, position transducers. ! High strength of diaphragms, springs and packings. ! Small size and weight.
（a）Direct-acting（PZMA） 1. Up diaphragm castings 2. Diaphragm 3. Diaphragm plate 4. Spring 5. Down diaphragm castings 6. Actuator stem 7. Yoke 8. Adjust nut 9.Travel indicator
Diaphragm Pneumatic Actuator
Website: www.valve-cn.com
（b）Reverse-acting （PZMB） 1. Up diaphragm castings 2. Diaphragm 3. Diaphragm plate 4. Spring 5. Down diaphragm castings 6. Actuator stem 7. Yoke 8. Adjust nut 9.Travel indicator
□ TECHNICAL PARAMETERS
□ MATERIAL FOR MAIN PARTS
Actuator Model PZMA/B-4 PZMA/B-5 PAMA/B-6 PZMA/B-7 PZMA/B-8
Effective area of diaphragm/cm2 280 400 600 1000 1600
Output Force (N)
20-100KPa 560 800 1200 2000 3200
40-200KPa 1120 1600 2400 4000 6400
80-240KPa 2240 3200 4800 8000 12800
Travel / mm 16 25 40 60 100
Suitable Control Valve
DN mm
Single/Double
Seated
20、25 32、40、50 65、80、100 125、150、200 250、300、350
Angle 20、25 32、40、50 65、80、100 125、150、200 250、300、350
Cage 20、25 32、40、50 65、80、100 125、150、200 250、300、350
Supply air pressure / MPa 0.14-0.3
Name of Parts Material Name of Parts Material Diaphragm Casting Q235 Spring 60Si2Mn Diaphragm NBR/EPDM Stem 2Cr13 Diaphragm Plate Q235 Yoke ZG25II
Diaphragm Pneumatic Actuator
Website: www.valve-cn.com
□ Connecting Dimension
Model D H2 H1 H0 M h1 n-d A B C E
PZMA/B-4 282 262 165 95 M10 15 / 45 / 65 25
PZMA/B-5 308 278 175 102 M10 15 4-10 54 72 91 25
PZMA/B-6 395 340 195 102 M12 15 4-12 54 80 106 30
PZMA/B-7 498 623 225 105 M16x1.5 20 4-12 70 98 130 30
PZMA/B-8 620 538 295 118 M20x1.5 20 4-14 100 130 162 30