6
Pressure Tech Ltd recommends the use of the following Lubricants during servicing:
-
Krytox GPL 205 lubricant
: For the O-rings.
-
Molykote 1000 paste
: For the adjusting screw.
Prior to commencing service, please ensure that:
-
The equipment has been de-pressurised
-
The load spring has been de-compressed by turning the adjusting mechanism fully
anti-clockwise
-
Applications involving toxic, flammable or corrosive media have been fully purged and
decontaminated sufficiently for safe service
To ensure the best possible results from servicing, when re-assembling the regulator and any
assemblies within it, ensure that all areas of the components and the regulator body are
cleaned and free from contaminants which may result in failure of the regulator.
6.1. Servicing the SS-231 (Balanced Design)
*Note: Fig 1 should be used as a reference for the following set of instructions
6.1.1. Accessing the Main Valve Assembly (MVA)
To access the Main Valve Assembly (MVA):
i.
With the flats of the regulator body (26) secured in a vice*, carefully loosen and
remove the bottom nut (20) using a 30mm socket or open-ended spanner.
*NOTE: Soft vice jaws must be used, when securing the body within the vice
against flats. (as without may cause damage to sealing surface for BSP O ring) Due
to the position of the flats it may be necessary to angle the body in the vice with
the bottom nut upright for access.
ii.
Lift the bottom nut (20) from the regulator body (26). The main valve (24) and
main valve spring (21) will be secured by the O-ring (4) and will likely come away
with the bottom nut (20), otherwise proceed to remove the main valve (24) and
main valve spring (21) from the assembly.
iii.
Carefully remove the soft seat (23) and O-ring (5) from the assembly*.
*NOTE: As the main valve assembly is a compression-based design, the soft seat
may be secured in the bottom nut upon its removal.
iv.
Where necessary, disassemble the soft seat (23), main valve (24) and main valve
spring (21) from the bottom nut (20).
v.
Visually inspect the sealing face (chamfer) of the soft seat (23) and the main valve
(24) for signs of damage and replace as required.
vi.
Remove and replace the O-rings (4 & 5) as required.
vii.
Install the 2x O-rings (6) around the bottom nut (20).
viii.
Place the bottom nut (20) on a flat surface and drop the main valve spring (21) into
the bore.
