Instruction Manual

Instruction Manual
D101643X012
ENVIRO-SEAL System - Rotary Valves
November 2011
11
Figure 7. ENVIRO-SEAL PTFE Packing System Detail
32B9116-B
NOTES:
APPLY LUBRICANT
THESE TWO SURFACES MUST REMAIN PARALLEL AS YOU ALTERNATELY AND EVENLY TIGHTEN THE PACKING NUTS.
1
2
Other Considerations
Note
The following check is only valid for rotary ENVIRO-SEAL packing systems and sliding-stem ENVIRO-SEAL or HIGH-SEAL packing
systems.
When retrofitting an existing packing system or repacking a valve with ENVIRO-SEAL packing that has been in service,
check the condition of the packing bore after you have removed the packing. An easy method for cleaning debris and
minor i mperfections from the bore is to use a brake cylinder hone attached to an electric drill. This method will do a
good job of cleaning the packing bore without changing the dimension of the bore.
When you have completed this exercise, a good guideline to use in checking the condition of the packing bore is the
20/20 rule. If less than 20% of the surface area of the bore is pitted and if no pits are deeper than 0.020 inch, then your
packing will work fine. This does not need to be an exact measurement; visual i nspection is adequate. If the packing
bore does not meet this criteria, however, you should replace the valve or have your Emerson Process Management
service center repair it.