VACUUBRAND BVC 21 - Manual (Page 21)

Documents are only to be used and distributed completely and unchanged. It is strictly the users´ responsibility to check
carefully the validity of this document with respect to his product. Manual-no.: 999054 / 15/12/2009
page 21 of 27
Assembling the connecting hose:
Reassemble in reverse order.
➨ Install head cover, valves and housing cover.
☞ Make sure that the valves are correctly seated: Valves at
the outlet with round centred opening under valve, valves at
the inlet with kidney-shaped opening beside valve.
➨ By turning eccentric bushing, bring connecting rod into up-
per turning point position (Max. stroke of the rod).
☞ Pay attention that the diaphragm stays positioned centrally
so that it will become clamped uniformly between housing
and head cover.
➂ ➂ ➂ ➂ ➂
➃
➀ ➀ ➀ ➀ ➀
➁ ➁ ➁ ➁ ➁
➨ Use open-ended wrench to assemble fittings with connection hose to the
pump head.
➨ Screw in four socket head screws fixing housing cover cross-
wise (e. g. in the sequence
➀ , ➁ , ➂ , ➃ ) first slightly, then
tighten.
☞ Do not tighten until head cover is in contact with housing,
torque 12 Nm.
If the pump does not achieve the ultimate pressure:
☞ In case the diaphragm and the valves have been replaced, a run-in period of several
hours is required before the pump achieves its ultimate vacuum.
If the specified ultimate pressure is not achieved and if this does not change after the
run-in period:
Check hose connectors at pump head for leaks. If necessary recheck pump chamber.
Individual performance check of a pump head:
By measuring the pressure at the inlet port of the individual
head:
Use a suitable vacuum gauge (e. g. DVR 2, cat. no.: 68 29 02),
make sure that it is correctly calibrated, and measure the pres-
sure at the inlet port. A vacuum of less than 110 mbar should
be indicated.
☞ If the reading is higher, recheck the pump chamber and make
sure that the valves and the diaphragm are correctly seated
(diaphragm concentric with bore).