Signedplate on back of rectangular piece: CENCO-MEGAVAC PUMP / U.S. PATENT NUMBERS / 1,385,101 - 1,719,747 AND 1,845,216 / OTHER PATENTS PENDING / TRADE MARK "CENCO" AND "MEGAVAC" / REG. U.S. PAT. OFF. AND FOREIGN COUNTRIES / MANUFACTURED BY / CENTRAL SCIENTIFIC CO. / LABORATORY APPARATUS (CENCO LOGO) SUPPLIES CHEMICALS / NEW YORK * BOSTON * CHICAGO * TORONTO * LOS ANGELES
raised lettering on side back of rectangular piece: CENCO / MEGAVAC
plate on motor: GENERAL (GE logo) ELECTRIC / AC MOTOR FOR DUAL VOLTAGE REPULSION-INDUCTION
at on end of the motor: (GE logo)
Inscribedplate on top of rectangular piece: DIRECTIONS / CENCO MEGAVAC PUMP / 1. FILL TO THE INDICATED OIL LEVEL WITH THE VACUUM / PUMP OIL SUPPLIED. / 2 TRAP ALL VAPORS TO AVOID CONTAMINATING THE OIL / AND CORRODING THE PUMP MECHANISM. / 3. OIL MAY BE DRAINED WHEN NECESSARY BY UNSCREWING / THE DRAIN PLUG IN THE BOTTOM OF THE PUMP CASE. REFILL / WITH CENCO NO. 11021 VACUUM PUMP OIL ONLY. / 4. ALL CONNECTIONS BETWEEN THE PUMP AND THE SYSTEM / BEING EXAUSTED MUST BE AIR TIGHT. FAILUER OF / THE PUMP TO PRODUCE THE GUARENTEED VACUUM IS / USUALLY CAUSED BY A LEAK IN THE SYSTEM. / 5. ANY OPERATING SPEED BETWEEN 300 AND 600 R.P.M. / IS SUITABLE. / 6. WITH THE ABOVE PRECAUTIONS THE CENCO- / MEGAVAC PUMP IS GUARENTEED TO PRODUCE A VACUUM / OF 0.0001MM OF MERCURY OR BETTER.
stamped on side of rectangular piece: U.S. PATENTS / 1890572 / 1890614
FunctionThe megavac vacuum pumps are a form of piston pumps, which are the reliable workhorses among vacuum pumps. They are used to evacuate large spaces to a decent, if not very high vacuum.
They are also connected as "first stage" to a high-vacuum pump to attain much greater vacuums.
This particular one has specifications for attaining vaccums of up to .1 microns (0.0001 mmHg).