ECO - REDUCED PRESSURE TEST EQUIPMENT
Introduction: The machine works on the Straube-Pfeiffer principal. Its purpose is togive visual indication of the gas content in aluminum prior casting. Molten aluminumsample is kept inside the specially designed SS chamber with a glass dome and therequired vacuum is attained in between 10 and 15 seconds. The molten sample is keptunder vacuum for about 5 minutes, and residual gas inside the sample is indicated onthe upper surface of the sample as well as very prominently indicated as blow holeswhen the sample is cut/machined. The size & the number of blow holes will depend onthe gas content of the sample.
The sample if cooled under atmospheric pressure will not indicate the gas content asthe one which has been cooled/solidified under vacuum and would have wronglypassed quality check prior casting.
Technical Description:
Vacuum Chamber:
The main component of this machine, so designed as to withstand highvacuum, as well as to attain vacuum by merely closing the lid without anyclamping required. The upper side of the chamber has a glass dome. The
chamber is tested upto 5 x 10-6 Torr.
Vacuum Pump – A high vacuum pump, driven by a 0.5hp single phase motor.
Suction Filter – One of the main component responsible for making the machine almostmaintenance free. The element is of stainless steel 25 micron mesh. The housing isdesigned in such a way that dismantling is done merely by opening only one butterflynut. The whole cleaning process can be achieved by a semi-skilled person in a matter ofminutes.
Vacuum Regulator – From feedback received from various users, it was found thatvarious alloys require different level of vacuum. This can regulate the vacuum from 20 –70 mbar (Effective range for vacuum sampling normally is between 70 – 90 mbar). Apreset regulator is located inside the machine, not easily accessible to casual tampering.
Control Panel – Over-load protection for the motor is provided. Various LED indicatorsare mounted on the panel. The vacuum indication is thru a digital display & vacuumsensing is done by a vacuum (pressure) transmitter.