The live loading provides a constant load over the life of the packing material.
Spring loaded valve packing.
Standard packing system optional live loaded packing system optional live loaded gland feature shown with the clampseal valve.
The high seal packing system is used in those.
This makes it a live loaded packing as opposed to a jam packing.
Integral gland wrench disc spring gland nose braided end wiper rings 2 die formed rings 2 double height bonnet seal backseat gland body stem surface finish 8 16 rms integral bonnet chamber stem guide the proper.
Live loading coupled with a very smooth stem surface provides a long service life with very low maintenance.
Photographs taken of an actual valve packing assembly removed from the bonnet left and reassembled on the valve stem right reveal the structure of the packing and associated components.
These systems are available for sliding stem valves with 9 5 12 7 19 1 25 4.
There is no lantern ring in this packing assembly but there is a coil spring.
High seal ulf live loaded packing system w5784 spring packing follower packing rings introduction scope of manual this instruction manual includes installation maintenance and parts information for high seal ulf live loaded packing systems see figure 1.
To understand live loaded stem packing we first need to understand what is stem packing and why it s used.
Belleville springs for valve live loading.
In its simplest form valve live loading is the application of a spring load to the gland follower of a packed valve.
Fisher easy e valve bonnet with enviro seal packing valve bonnet belleville springs valve packing stem flange packing follower w5814 1 live load spring design.
Springs are not available in all alloy materials.
Spring type packing can be recognized as having the packing follower drawn against the bonnet to compress the spring.
Jam type packing with lantern rings.
Determining if your valve application is a candidate for live loading can best be decided by answering yes to any of the following questions.
If a special alloy is required it may be necessary to consider packing with lantern rings.
The lowflow mk708 control valve uses live loaded stem packing to provide maximum containment of liquids gases or steam inside the valve.
Valve stem packing as one.
The spring load will be slightly reduced as the springs expand but this reduction in load will be much less than the load that is lost if the packing set was not live loaded.
Spring thickness is less than the stud thread root usually done with external sleeve sleeve is used to measure relaxation in packing.
From a user perspective enviro seal packing is most typically thought of as an emission reducing packing system.
Valve stem the valve stem is the part in a valve which converts the actuating force into opening closing motion.
Of spring is too large for the gland stud metric springs used with inch studs sleeve is used to limit torque.