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Parr Instrument Flexible Graphite Gaskets User Manual

Flexible graphite gaskets sealing instructions, 285m

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Flexible Graphite Gaskets

Sealing Instructions

285M

The amount of torque required to seal a pressure

vessel is a function of the intended operating

pressure.

The closure bolts may be tightened using either

an open-end wrench for smaller vessels where

the bolt torque requirement is less or with a

torque wrench where additional loading is re-

quired for the higher operating pressures.

Some of the gasket numbers shown in the at-

tached table are furnished with vessels that have

different maximum working pressures. We have

shown the maximum torque value to correlate

to the maximum working pressure of the vessel.

It is important to make sure that the bolts are pe-

riodically lubricated with a high-temp anti-seize

compound to insure that they move freely so

that the desired torque value is obtained in the

tightening procedure.

It is also important to insure that there is uniform

loading on all of the bolts. Make sure that the

head sits levelly on the cylinder. Install the split

ring and tighten all bolts finger tight.

Pick a starting position and tighten the bolt to 5

or 10 ft-lbs depending on the maximum amount

of torque to be applied. For those vessels with

a maximum torque requirement of 15 ft-lbs, a 5

ft-lb increment is appropriate. For vessels with a

maximum of 135 ft-lbs, 20 ft-lb increments may

be used.

Bolt tightening should continue in a criss-cross

pattern from the initial bolt with the second bolt

180 degrees from the first and continuing until

all bolts are tightened. Repeat this procedure

increasing the torque to the required level as

shown in the table below.

Note:

It may be possible to extend

the life of the flexible graphite gasket

by coating both sealing surfaces of the

head and cylinder as well as the gas-

ket itself with a silicone base lubricant.

Additionally, it helps to rough up the

cylinder lip with 120 grit sandpaper to

insure that the gasket remains in the

head recess and does not stick to the

cylinder.

Parr Part No.

Pressure (psi)

Torque (ft-lb)

315HC4KL

1900

35

429HC2KL

3000

3000 to 5000

15-20
20-25

457HC3KL

3000

5000 to 6000

35
40

655HC3KL

1900

35

1808HCKL

5000

40

1812HCKL

3000

35

1829HCKL

8500

15

1559HC2KL

1900

135

2303HC2KL

5000

55

Recommended Bolt-Torque for Flexible Graphite Gaskets

P

arr

I

nstrument

C

ompany

211 53rd Street • Moline, Illinois 61265 USA 1-309-762-7716 • 1-800-872-7720 • Fax: 1-309-762-9453

E-mail: [email protected] • http://www.parrinst.com

285M R04 Revison 11/05/13