Habonim Catalog Interactive 2021 V04 070621 - Flipbook - Page 31
High Cycle (HC) Stem seal
High cycle service is defined by Habonim engineering as continuous operation for more than
one hour at a frequency greater than 1 cycle / 180 seconds.
When designing a valve for high cycle service parameters, such as heat dissipation due to friction
of metallic and plastic parts, resistance to fatigue stress, and mean time between maintenance
activities must be taken into consideration.
For high cycle applications Habonim recommends the use of valve stems made of high tensile
material. The stem will be polished for a high degree of surface roughness. The stem thrust
seal will always be made from highly wear-resistant plastic material. A Viton O-ring is inserted
into a customized follower. The complete trim assembly is preloaded by a double or even triple
Belleville spring stack. All of these design features give the valve a particularly long service life.