Seetru G27 Instructions Manual

MINI GAUGE G27

Issue: 3
Date: 12.10.10

General Description

The Seetru Mini Gauge consists of a transparent sight tube, protected against breakage by a transparent
polycarbonate guard tube or Stainless Steel with viewing slots.

The sight tube is sealed into collars at both ends which in turn are fixed and sealed to the tank by connection
nipples.

Installation Instructions

Tank connection thread of ¼” BSP.PL. is required [standard Mini Gauge connection].Ensure good surface
for flat face seal.

1. The gauge should not be fitted to tank bosses whilst welding bosses to tank, to avoid heat soak
damage to seals.

2. After welding, check face and bore of tank boss [or tank face if bosses have not been used] is free of
damage and weld splatter. Ensure correct alignment and squareness of top and bottom tank
connection to avoid undue strain on gauge.

3. Fit gauge assembly up to tank, ensure seals are in position on collar, screw nipples (item 9) into tank
to seal gauge to tank. Tightening torque of 12 – 16Nm MAX.

4. Gauge may be adjusted by +/- 2mm on nominal centre distance by slacking off gland nuts and
sliding the collars on the sight tube, retighten gland nuts after adjustment.

The gauge is now ready for service, check for leaks.

Important

Nominal centre distance must not be exceeded by 1.6mm as this could affect the gauge sealing and re­assembly of the gauge, as per maintenance paragraph, will be necessary.

Operation Faults Table

FAULT

PROBABLE CAUSE

RECTIFICATIOIN

Empty tank Fill tank

Gauge not filling

Obstruction in gauge Clear

Mis-use Renew

Broken sight tube

Mis-alignment Renew, check face flat

Loose retaining nut Tighten

Leaks from collar seal

Damaged 'O' ring Renew

Loose gland nut Tighten

Sight tube gland leaking

Damaged 'O' ring

Renew

Nipple loose Tighten

Leaking from tank boss

Sealing washer damaged Renew

2

MINI GAUGE G27

MAINTENANCE

Before undertaking any maintenance work on gauge, ensure discharge of gauge or tank cont ent will not
create a hazard to personnel. Particular attention being given to hazardous fluids, system temperature and
pressure.

TO REPLACE SIGHT TUBE, CLEAN GAUGE OR REPLACE SEALS

1. Drain tank.

2. Unscrew top and bottom nipples (9) remove gauge assembly from tank.

3. Remove nipples from collar (8).

4. Check and renew seals (10) if required.

5. Unscrew top gland nut (4) from gauge collar (8)

6. Remove top gauge collar (8) from tubes by pulling.

7. Remove guard tube (2) by sliding off sight tube.

8. Unscrew lower gland nut (4) from lower gauge collar (8).

9. Remove sight tube (1).

10. Clean or renew sight tube, inspect all bushes and seals (5, 6 & 7) renew if required.

11. Check internal passages of collar and nipples are clear of obstructions.

12. Refit lower gland nut, bushes and seals to sight tube.

13. Screw lower gland nut to lower collar.

14. Refit guard tube.

15. Refit upper gland nut, bushes and seals to sight tube.

16. Screw upper gland nut to upper collar.

17. Gauge is now ready for refitting to tank.

3

MINI GAUGE G27

Assemble as follows:
Gland nut (4) to be placed over sight tube (1), then one ferrule (7), large O’ring (6) SXX01433, small O’ring
(5) SXX01333, then the second ferrule (7), which should then be pushed into the collar (8) and the gland nut
(4) to be screwed onto the collar (8) and tightened to 12Nm.