Flushed Single Mechanical Seal; Flushed Single Mechanical Seal Removal; Flushed Single Mechanical Seal Installation - Unibloc-Pump LABTOP 200 Series Operation And Service Manual

Table of Contents

4.4.2 Flushed Single Mechanical Seal

The flushed single mechanical seal uses the same stationary mating ring, rotating seal nose ring, spring, and o-rings as the single

mechanical seal discussed in section 4.4.1. The drive collar is different, however. The flushed single mechanical is not available

for UNIBLOC 200-0, 200, 250, and 275. See section 3.3 for more information about flushing systems.

Disconnect the flush tubing from the flush housings (55). Loosen the set screws

(D) by inserting an allen wrench into the flush housing port holes. Loosen the stud

nuts (43). Remove the rotor housing (1) by pulling on the ports or by tapping

gently with a rubber mallet and lay it rotor cavity down so that the seals face up.

Do not rock the housing back and forth excessively or let it come in contact with

the shaft splines. The seals may break. The entire seals with the flush housings will

come off intact with the rotor housing. Unscrew the bolts (32) to remove the flush

housings (55), the lip seals (56), and the flush housing o-rings (37). The remaining

seal components may now be removed. To avoid damage, handle and store the

loose seal nose rings (B) and the mating rings (A) so that their lapped sealing

surfaces do not get scratched. To remove the lip seals (56), place the flush housings

so that they are supported at the bolt holes not at the at the o-ring (37) location.

This can be done by placing the flush housings, after all other seal parts have been

removed, back into the rotor housing seal bores. Push or tap the lip seals with a

tube to remove them.

Place the mating ring o-rings (33a) in the rotor housing seal bores. Only lubricate these o-rings with water or alcohol. Push the

mating rings into the rotor housing so that they seat flat with the step in the housing. Do not use objects that will scratch the

mating rings' seal surface to push them in. Check the drive collars (C) for wear at the lip seal location. If a groove is present, the

drive collars may need to be replaced. If the lip seals (56) have been removed, place the flush housings (55) so that the o-ring

groove edges face up. Lubricate the lips and the outer diameters of the lip seals. Push the lip seals, spring sides facing up, into the

flush housings with a tube that is the same diameter as the lip seals. Place the o-rings (37) into the o-ring grooves. Lubricate the

shafts, the outside of the plastic mounting sleeves, and the drive collars at the lip seal location. Slide the flush housings on the

drive collars. Slide the flush housings with the drive collars, seal nose o-rings (33b), and the seal nose rings (B), slotted sides first,

on the plastic mounting sleeves. Align the slots with the pins in the drive collars and push the seal nose rings so that the o-rings

(33b) seat properly. Place a product compatible lubricant on the sealing surfaces. Rotate the flush housings so that its port holes

align with at least one set screw. Lubricate the o-rings (37) and mount the seal cartridge assemblies on the rotor housing. Tighten

the bolts (32). See section 4.4.5 to complete the installation.

Page 18 of 4

Table of Contents