Groth 7758A - Manual (Page 5)

MAINTENANCE
For maximum operating efficiency the element of a
flame arrester must be inspected and maintained at
regular intervals. Frequency of inspection should
be based on the experience gained in each
application. Inspection of wetted components is
recommended at least once per year or any time
that one of the following conditions occurs:
•
Excessive pressure drop is encountered at a
known flow rate.
• A flame front is detected.
Maintenance is accomplished by removing the
element assembly for inspection and cleaning or
replacement.
CAUTION
The connecting pipeline must be free of all hazardous
or flammable vapors before inspection procedures
begin. Before disassembling arrester consult Material
Safety Data Sheets (MSDS) for all products that the
arrester was exposed to in service. The components
should be cleaned according to MSDS procedure.
Take appropriate safety precautions regarding eye
protection, skin contact & respiration.
1. When removing the element housing for
maintenance, support the weight by attachment
to the housing handles, or lifting eyes, and
proceed as follows.
WARNING
Handles or lifting eyes on the element
housing are to be used for handling the
housing only during inspection and
maintenance. DO NOT use these eyes to lift
the entire detonation flame arrester assembly.
2. Loosen the hex nuts and remove only those
studs or tie rods necessary to withdraw the
housing.
3. On the remaining studs, loosen the holding nuts
and use the spreader bolts to separate the base
halves from the housing. Use spacer blocks or
spreader tools, if necessary, to safely secure
the base halves so the housing is free for
removal. The remaining studs will support and
position the housing.
CAUTION
In a horizontal line, the flame bank assembly
should be supported before removing the
studs. Use structures and equipment suitable
for supporting the components weight. The
weight is noted on the drawing later in this
manual.
4. Remove the housing assembly for inspection.
The flame element and supporting grids shall
be visually inspected for damage or corrosion
build-up from both sides. If the flame element
appears to be damaged, it should be replaced
immediately with a new one.
5. Inspect the surfaces of the element for
corrosion or foreign material that appears to be
restricting the passageways. If the flame
element is plugged it can be cleaned by one of
the following methods:
• Compressed air.
• High pressure steam or water purge.
• Solvent wash followed by compressed air.
• Wire brush cleaning the element surface.
6. Inspect the sealing gasket for damage and
replace if necessary.
7. Reassemble the housing, elements and
gaskets. Tape the gaskets to the housing with
a thin tape, such as masking tape. Then insert
the housing assembly between the base
flanges.
The studs will position the housing on the base
centerline. Insert the studs and torque all
fasteners to half the value listed in Table 2 in a
staggered, alternating pattern to provide an
evenly compressed gasket joint.
Lubricate all studs and nuts with an appropriate
thread lubricant. If the arrester will see high
temperature service or stainless steel fasteners
are used, select an anti-seize compound such
as moly-disulfide.
8. Make up the final torque and check that no
further nut rotation occurs at the specified torque
value. The torque values are based on original
gaskets supplied by Groth Corporation.
IOM-7758A
Ref. ID 97895
4