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Manual BR11 Version 1.2 19.11.2019
4. OPERABILITY, MAINTENANCE AND REPAIR - STANDARD CONSTRUCTION
The operability of the regulator valve during use is based on maintaining an appropriate flow characteristic and not
exceeding the permitted leakage level for the valve.
To ensure long-term correct and safe operation of the valve, it is essential to carry out regular recorded inspections. Valves
that operate continuously should be checked at least every 6 months. Valves that operate discontinuously should be
checked at least every 12 months.
If it is necessary to carry out maintenance or repair work on the regulator valve, it should be carried out as follows:
4.1. Gland packing
A key criterion for operability is external seal-tightness, which is provided by the gland packing.
The gland packing to be used is normally pre-specified based on the operating conditions.
With normal gland packing, the tightness of the seal is achieved by tightening the sealing nut.
WARNING:
When the valve is supplied, the sealing nut is only hand-tightened. Before putting the valve into service, it is
essential to tighten the sealing sufficiently to achieve an adequate contact pressure, thus ensuring a secure
external seal, but without blocking the valve spindle.
If self-adjusting sealing glands are used, the constant contact pressure is provided by a stainless steel spring. For this
reason, the sealing nut should be screwed in up to the stop.
To change the gland packing, proceed as follows:
Before changing the gland packing, ensure that the valve is not under pressure and is not contaminated.
1. Loosen the upper part of the valve by opening the casing nuts (21) between the casing and the top of the valve.
2. Lift the upper part of the valve out of the casing, along with the valve spindle and the valve block. Loosen the coupling
nut and counter-nut (35,37) and the lock-nut (36), and unscrew them from the valve spindle.
3. Undo the sealing nut (or screw plug) (12) from the sealing gland, and withdraw the valve spindle and valve block from
the upper part of the valve.
4. Using appropriate tools, remove all parts of the sealing gland (13,14) from the gland packing space, and carefully clean
out the packing space.
5. Fit a new casing gasket (15) and carefully clean the surfaces of the seal in the casing and on the upper part.
6. Insert the valve spindle and the valve block into the upper part of the valve.
7. Carefully locate the upper part of the valve on the valve casing and fasten it in place with the nuts (19).
8. Carefully fit the new sealing gland parts over the valve spindle and into the packing space, taking care to get everything
in the correct order (insert the parts in reverse order to the order in which they were taken out).
9. Screw on and tighten the packing seal nut (12).
10. Screw the counter-nut and coupling nut (35,37) and the lock-nut (36) on to the valve spindle and connect the drive and
the valve solidly back together.