The LP disc pack couplings range, made by R + W and available in the UK from Drive Lines Technologies Ltd, has been expanded with new sizes and updated to meet the latest API (American Petroleum Institute) standard API 610 for centrifugal pumps in the petrochemical industries.
Disc pack couplings consist of two coupling hubs and a spacer tube mounted to the disc packs by high-strength screws and bushings. The disc packs are made of highly elastic, corrosion-resistant spring steel, while the hubs and spacer are made from high strength steel materials.
The updated models maintain the range's established reputation for transmitting power solely by friction between the discs, with no shear forces being exerted on the bolts. This ensures an even distribution of load and thus avoids stressing of the bolts, minimising wear and, consequently, premature failure.
R + W has doubled the number of sizes of disc pack couplings it offers. The torque remains from 300 to 12,000 (Nm) rated torque and maximum torque ranging from 700 to 24,000 (Nm), but an extra intermediate option between each existing size has been introduced. This means that users can choose an optimum sized coupling rather than having to fit an oversized one.
There are also more options for customisation, such as shorter intermediate spacers, fully split clamping hubs, and longer drive shaft. R + W expects that about half of users will require couplings that are significantly customised, hence the flexibility built into the new range.
Within the range, the LPAI model also meets all the requirements of API 610, ISO G6.3, and AGMA class 9 for minimum balance quality. It features an intermediate tube that is removable without disturbing adjacent equipment and has an integral safety catch in case of disc pack rupture.
API 610 relates to centrifugal pumping applications in the oil, gas and hydrocarbon industries, but also includes a section on couplings which defines the balance and handling requirements that need to be met so that smooth running is maintained at all times.
In summary, the LPAI is a low-wear and maintenance-free coupling that allows for easy handling to access pumps and motors without having to disturb the adjacent equipment.
To help comply with API 160, the LPAI is described in Imperial physical dimensions and performance ratings rather than metric, a first for R+W.
For more information about the R+W LP disc pack couplings range please go to www.drivelines.co.uk.