612J 230/460V, 3-ph, 60Hz (230/460V Coil)

The Stokes Microvac rotary piston pump sets the standard for performance and reliability as the industrys most efficient, space-saving design. The Stokes Microvac rotary piston pump has been improved, upgraded, and fine-tuned to deliver even better dependability and productivity combined with minimal maintenance and process downtime.

An integral oil distribution system eliminates external piping and delivers leak-free operation in a stylized design. A stiffer motor mounting platform cuts flexibility to minimize motor belt wear. A stylized oil reservoir cover and side cover ‘O’ rings improve sealing to eliminate oil leakage. An integral gas ballast valve built into the side cover allows quick adaptation to automatic gas ballast.

Most importantly, these improvements don’t increase the industry leading space saving footprint. Inlet, outlet and mounting dimensions are exactly the same as the H series Microvac rotary piston pump.

This pump is fitted with a 230/460V coil for control of the oil solenoid valve which prevents the pump from flooding with oil in the case of power failure or a loss of vacuum. In addition oil temperature/heater ports have been added as standard to provide a means to monitor and heat the pump oil if required.

The Microvac 412J pump is a self-contained, rotary, oil sealed piston type unit. The pumping piston is mounted to the main drive shaft via an eccentric and supported by two free oscillating hinge bars. When the piston rotates, air enters the pump through the piston slide. As the piston reaches the top-center position, the intake port is closed. The entrapped air is then compressed and discharged through the exhaust valves and out the reservoir exhaust outlet as the piston continues to rotate.

Lubrication of the internal components of the pumps is completely automatic. This pump is fitted with a 230/460V coil for control of the oil solenoid valve which prevents the pump from flooding with oil in the case of power failure or a loss of vacuum.

To allow pumping of high vapor loads, an integral gas ballast is fitted. This is used to prevent condensation of the vapor carried by the pump gases.

• Automotive
• Chemical processing
• General applications
• Heat treatment
• Leak detection
• Metallurgy
• PET processing
• Pharmaceuticals
• Transformer drying and cable fluid conditioning
• Vacuum coating
• Vacuum melting

• Robust cast and ductile iron construction provides proven rugged reliable operation.
• Low 500rpm operation for longest pump life cycle.
• Efficient design provides maximum uptime with minimal moving parts, low rotational speed and large clearance.
• Low ultimate blank-off with pressures down to < 2.5 x 10^-2 Torr.
• New valve deck design virtually eliminates valve maintenance and noise.
• Space saving design which saves up to 50% of valuable floor space.
• Complete and self-contained unit delivered ready to install.
• Automatic lubrication system provides proper flow of oil to bearings and sealing surfaces and prevents back flow into system.
• Controlled balancing reduces vibration to a practical minimum.
• Gas ballast as standard.
• Total capability includes the manufacturing and service capabilities to keep your equipment in top operation with a broad range of vacuum system accessories.

Displacement (swept volume)	1020 m3h-1 / 600 ft3min-1
Pumping speed	884 m3h-1 / 520 ft3min-1
Ultimate vacuum (total pressure)
without gas ballast	<3.3 x 10-2 mbar / <2.5 x 10-2 Torr
with gas ballast	<2.6 x 10-1 mbar / <2 x 10-1 Torr
50Hz Motor size	11 kW IEC (CE variant) (x2)
60Hz Motor size	10 hp TEFC (x2)
Motor speed	1800 rpm
Inlet connection	6 inch ASA/ANSI flange
Exhaust connection	2 x 3 inch ASA/ANSI flange or 3 inch NPT
Cooling medium	Water
Water inlet/outlet connection	2 x ½ inch NPT
Recommended cooling flow @ 85°F / 30°C	7.6 lmin-1 / 1.5 galmin-1 (x2)
Water vapour pumping rate	20.9 kg h-1 / 46 lb h-1
Oil capacity	92 litre / 24 gal
Recommended oil	V lube F
Noise level	<85 dB(A)
Weight	1724 kg / 3800 lbs

1. Without gas ballast      2. With gas ballast