General manufacturer specifications for reciprocating, oil-free, non-lubricated diaphragm gas compressors

Based on our extensive experience in compressor technology and our state of the art engineering and gas compressor manufacturing capabilities, we work with our customers to provide the optimal solution to satisfy their process gas compression needs.

PDC Machines provides standard manufacturer and custom-designed diaphragm gas compressors with a comprehensive assortment of options. We can provide simple push button controls or sophisticated PLC controlled compression systems to meet any application. Discharge pressures range from 50 psi to 60,000 psi (3.4 bar to 4137 bar), power consumption from 3 hp to 200 hp. (2 Kw to 150 kW) and flow rates based on compression ratio to over 3000 Nm3/hr.


diaphram gas compressor manufacturer by PDC Machines

PDC-13-1250-3000 two stage diaphragm compressor manufacturered by PDC and installed in United Arab Emirates for feeding hydrogen gas into a reactor at a flow rate of 400 Nm3/hr at a discharge pressure of 200 bara. Horse-power is 125 hp (93 kW) for manufacturing plastic. This reciprocating diaphragm compressor meets plant codes and standards. The scope of supply is a turnkey system including inlet and outlet pulsation dampners, pressure and temperature transmitters for all stages, segregated junction boxes.  100% Welded and Radiographed Process Piping & Vessel joints.


Manufacturing scope of supply

Basic compressors
The basic single-stage reciprocating diaphragm compressor includes a static conductive, oil resistant V-belt drive system, non-sparking OSHA belt guard, electric motor with adjustable rail, welded steel framework, diaphragm failure leak detection system, after-cooler and inlet filter.

Two-stage compressor includes the above as well as an inter-stage gauge, inter-stage accumulator, inter-stage relief valve, inter-cooler and after-cooler.


two stage hydrogen gas compression system

PDC-3-550-2500 (50) two stage diaphragm compressor delivering hydrogen at 8 Nm3/hr based on 80 spi (5 barg) suction, 3000 psi (200 barg) discharge. Horse-power is 5 (4kW). This fully automated compressor complete with instrumentation and controls for operating without any attendants is used for cooling power plant turbines.


Instrumentation and controls
A standard manufactured diaphragm compressor complete with instrumentation and controls includes the basic compressor, noted above, as well as a control panel, transformers, relays, motor starter, start-stop button, suction pressure switch, discharge safety pressure switches (Hi) and (Hi-Hi), suction and discharge pressure gauges, water flow indicator and switch, temperature indicators, and automatic unloading system. PDC Machines can supply a hard-wired relay logic control or fully programmed PLC system.

Additional components for plant applications as required by Engineering, Procurement and Construction firms can include pressure and temperature transmitters, double block and bleed valves, 2oo3 voting, pulsation dampeners, single or double safety relief valves, capacity flow control, and an HMI (Human Machine Interface).

Where water cooling is not available, PDC Machines can supply a closed loop water cooling system fully integrated into the skid.  For larger models we provide a chiller.

PDC Machines can provide a crank case heater with switching thermostat along with heat tracing for the hydraulic piping and heads.  This is appropriate for temperatures below 40oF (4 oC), to avoid excessive increase in the hydraulic oil viscosity at these temperatures.

Highly reactive gases
For compression of oxygen, fluorine and other highly reactive gases, PDC Machines performs rigorous cleaning procedures in accordance to its customers requirements.  We use fire-resistant oil for the hydraulic system. We construct the process side diaphragm, as well as the inner and outer check valve components.


duplex diaphragm gas compressor manufactured for India

PDC-4-600-600 (130) Duplex diaphragm compressor for hydrogen service installed in India.  This compressor skid complies to IEC Zone II Ex d IIC T3 and conform to weatherproof rating of IP66.   Instrumentation includes pressure and temperature transmitters meeting intrinsic safety EEx d and EEx ia. All pressure gauges and transmitters equipped with integral valve manifolds.  2oo3 (two out of three) voting logic implemented for all shut down set points pertaining to pressure or temperature.


Codes and standards

PDC Machines designs and manufacturers our products to comply with a wide range of domestic and international standards:
• American National Standards Institute, ANSI
• American Society of Mechanical Engineers, ASME
• American Welding Society, AWS
• Canadian Standards Association, CSA
• Canadian Registration Numbers, CRN
• CE marked, European Union
—-– ATEX Directive
—-– Pressure Equipment Directive (PED)
• ATEX Directive
• Pressure Equipment Directive, PED
• Chinese, SQL
• The High Pressure Gas Safety Institute of Japan, KHK
• Korean Gas Safety, KGS
• Korean Occupational Safety and Health Agency (KOSHA)
• National Electric Code, NEC
• National Fire Protection Association, NFPA
• Occupational Safety & Health Administration, OSHA
• Underwriters Laboratories, UL, cUL
• Russian certificate of conformity, GOST-R


reciprocating diaphragm compressor manufactured by PDC Machines

PDC-13-1250 Reciprocating Diaphragm Compressor. Suction Pressure: 24.5 BARG, Discharge Pressure: 80 BARG, Required Flow Rate: 45 Kg/Hr Hydrogen Gas, HP: 55KW (~75HP). This compressor included an ESD (emergency shut-down) control philosophy for each monitoring point throughout the system; thermowells for the process RTDs, block and bleed integral manifold valves for all pressure transmitters; 4 separate junction boxes in addition to the Local Control Panel. All process piping was butt-welded and 100% radiographed, and all cooling piping was socket welded.