Housing with upper flange made of machined and hardened steel. Machined steel cover cap.* Felt sealing system.** Self cleaning bottom hole. Housing available in steel, zinc plated steel, stainless steel. Chrome steel, AISI 420C stainless steel, plastic material balls. * For SPM 12 – 25 in pressed metal sheet. ** Except SPM 12 – 15 – 25 and types with the large ball in plastic material.
