SPX TG H15-50, Instruction Manual, Page: 44 / 110

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Bd (Bi)
Bj
A 3050 B
A.0500.351 – IM-TGH/07.02 EN (10/2015)
3.18.8.4 Double mechanical seal – Back-to-back arrangement
• Use connection Bd or Bi as the outlet of
quench media and one of the connections
Bj as the inlet.
• Use connection Bc as filling and air release plug
(this is not possible with H2-32/H3-32 and
with jackets around the shaft seal area).
• Let the media circulate between the sliding faces (B)
at 1-2 bar overpressure with regard to the pressure
in the sealing space at pump side (A).
Under normal circumstances the pressure in the
sealing space (A) is equal to the suction pressure
plus half the differential pressure (
∆
p).
Locking ring
At the first mechanical seal (liquid side) an axial locking ring can be mounted (also consult
section 4.7.7.3 or EN12756 (DIN24960).
This locking ring prevents the static part of the mechanical seal from being pushed out of its seat
in case quench pressure (B) falls back or drops out.
This locking ring must be adapted to the static ring and must be delivered together with the
mechanical seal.
Some mechanical seals are designed in such a way that the stationary ring can not be pushed out
of its seat. In that case, there’s no need to fit a locking ring.
3.18.8.5 Cartridge mechanical seal
The cartridge mechanical seal can be delivered in several configurations:
• Single mechanical seal with throttle bush (leak control or steam quench) (GCT)
• Single mechanical seal with lipseal (liquid quench)(GCQ)
• Double seal arrangements (GCD)
•
Triple lip-seal (LCT TV / LCT XX):
low pressure quench and/or leak detection between 2rd and 3rd lip-seal
For details and flush/quench connections, see figure in section 4.7.7.4.
Axial locking ring at the first mechanical seal
Design double mechanical seal without
locking ring