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Preformed graphite seals
Gland packing sets, soot blower sets, valves and control valves.
There are two ways to pack a gland. One is to cut lengths from a coil of packing rope and wind them in. The other is to fit rings that were pressed to the exact size of that gland before they arrived.
The second is more work to make and considerably less trouble afterwards.
Gland packing sets, soot blower sets, valves and control valves.
Why die-formed rings behave differently
Packing cut from rope has a joint. It has to — you cut a length and close it around the stem. That joint is a leak path, and the ring-3 has no defined density until it is compressed in place, which means the installer's technique determines the seal.
A die-formed ring-3 is pressed in a die to the exact inside diameter, outside diameter and height of the gland it is going into. It arrives at a known density, with the joint closed under pressure rather than butted together by hand.
The practical differences:
- Less gland load is needed — to get a seal, which means less friction on the stem and less wear
- More consistent from one ring-3 to the next — and from one fitter to the next
- Better resistance to extrusion — at pressure and temperature
- Fewer emissions — past the stem, which matters where the medium is not something you want in the air
Where flexible graphite is used
Flexible graphite handles temperature that most other packing materials do not, and it is chemically inert across a wide range. It is the standard choice for:
- Refining and petrochemical — valve stems on hot service, steam and hydrocarbon duty
- Power generation — steam valves and pump glands
- Chemical plant — aggressive media where an elastomer or PTFE would be attacked
- Pulp and paper — steam and hot liquor service
It runs where an O-ring would harden and a PTFE ring-3 would cold-flow.
Soot blower sets
Boilers use soot blowers to keep their tubes clean. A lance travels into the boiler, turning as it goes, and blasts the build-up off the tubes with steam or air. The packing around that lance works harder than most: it has to hold back high-pressure steam while the lance spins and slides at once, and wipe the ash off the lance on its way back out.
We make soot blower sets to fit your stuffing box: V-shaped (chevron) rings in the middle that open up under pressure to seal, with a matching ring at each end to seat the set. Every set is die-formed to size, in flexible graphite for high-temperature steam, hot water and gas, or in carbon-filled PTFE (C.P.T.F.E).
Because each set is made to size, the make of soot blower doesn't matter. Send us the lance diameter, the stuffing box bore and depth, or an old set, and we will make one to match.
1 / 3High-pressure preformed seals
For high-pressure duty we make HP preformed graphite seals with stainless steel caps, pressed to size like the rest of our graphite sets.
Getting the size right
The ring-3 has to match the gland, not approximately but exactly. What is needed:
- Stem or shaft diameter — the inside of the ring-3
- Bore of the stuffing box — the outside of the ring-3
- Depth of the stuffing box — and how many rings are going in
- Temperature and pressure — in service
- The medium
If you have an old ring-3, send it. It gives us the section and the ring-3 height directly.
What we need from you
The measurements above, or a sample ring-3, or the valve number and a photograph of the gland area.
Send it through and we will quote it.
Enquiry
Send us your part.
Tell us what's broken, worn or needed from scratch. Photos and drawings help. We'll quote it and get back to you.