A rotary valve, in its simplest form comprises three main elements. A body, a rotor, and a drive system.

One essential element in the trouble-free running of a rotary valve is maintaining the seal around each end of the rotor shaft where it passes through the end covers. Most valves use a simple sealing arrangement comprising gland packing, under pressure within a machined recess in the end cover, sometimes known as the stuffing box.

Gland packing is a square section rope manufactured using a range of materials to best suit the application.
The most common type of packing in rotary valves is PTFE which has good low temperature characteristics and offers low friction properties. Other gland packing materials are utilised for differing applications such as high temperatures or hygienic/food applications.

By installing multiple rings of packing within the gland housing and then pressurising them by means of a simple gland follower an effective seal is achieved around the rotor shaft. Properly installed gland packing prevents product passing through the end cover and wear due to erosion is largely eliminated.

It is essential that the gland packing is under enough pressure to achieve an effective seal and that it has not degraded.
The pressure on the gland packing is achieved by adjusting the gland follower such that it moves towards the end cover, exerting pressure on the packing. Once the gland follower has been adjusted to its physical limit, it is critical that the packing is replaced.
Most incidents of product leakage from a valve or wear to rotor shafts will be through the incorrect maintenance of gland packing.

Rotolok stock a range of gland packing for all applications including high temperatures and food grade packing, across all valve sizes.
We also stock replacement gland followers.

If you have any questions regarding gland packing or other aspects of valve maintenance please contact our Sales team.

+44 (0) 1884 232232

What our customers say

"I wanted to congratulate the entire team at Rotolok on the initial sales consultation, after sales support, technical documentation and most importantly the quality and reliability of your finished product. Notably the two ATEX certified rotary valves we bought from you last year have been faultless!" Rob Rogers, Technical Director, Gough Engineering
"You delivered the first 2 rotary valves in around 3 weeks, which was not only 1 week sooner than you quoted me, but an impressive 17 weeks faster than I was quoted by a competitor of yours!!” Richard Stanton, RAS Extraction Ltd
“I would like to take this opportunity to express my thanks to every staff member at Rotolok for their sincere support throughout. I would definitely recommend Rotolok to be considered on our future projects where advice is sought” Mechanical Engineer, Multi-National Project Management Consultancy
"We have been working with Rotolok for many years, throughout we have been overwhelmed with the product quality and especially the communication." General Manager, Major OEM Supplier, Lithuania
“The RotoFlex Valves arrived today and I could not be happier with them!” James Saker, Maintenance Technician at DDW, The Color House
“You may not know this but I bought twenty 250 drop through seals from Dan McCauley when he first started up in the mid to late 70’s. I think I picked them up from his home near Gatwick- they are still running perfectly!!” Duncan Marston, Former Director at C Marston and Sons (Now known as Heygates, Icklingham)
"Thank you so much for the prompt response and great support as always!” Multinational Consumer Goods Manufacturer
"I was really happy about the service and the fast responses I received.” Mischa Ruf, Process Engineer, Ingelia
"The specification was exactly as ordered and the Rotolok valve worked very well in every moment of production. We appreciate the interest to deliver the perfect product for our application." Alessandro Gonzalez, Mechanical Designer, IRIS S.R.L, Italy