BS ISO 6182-6-2015 pdf download.Fire protection一Automatic sprinkler systems一 Part 6: Requirements and test methods for check valves. 4.7.5 Sealing surfaces of sealing assemblies. including the sealing assembly seat ring, shall have corrosion resistance equivalent to brass or bronze and have sufficient width of surface contact to withstand ordinary wear and tear, rough usage. compression stresses and damage due to pipe scale or foreign matter carried by the water. 4.7.6 Springs and diaphragms shall not fracture or rupture, when tested in accordance with 6.2. 4.7.7 There shall be no sign, on visual examination, of damage to the sealing assemb’y after testing for the operational requirements in accordance with 6.10. 4.7.8 When wide open, the sealing assembly shall bear against a definite stop. The point of contact shall be located so that impact or reaction of the water flow will not permanently twist, bend or fracture valve parts. 4.7.9 Where rotation or sliding motion is required, the part or its bearing shall be made of a corrosion resistant material. Materials lacking corrosion resistance shall be fitted with bushings. inserts or other parts made of corrosion resistant materials at those points where freedom of movement is required. 4.7.10 The sealing assembly shall close towards the seat when water flow ceases. Springs shall be permitted to ensure full and proper seating. 4.8 Leakage (see 6.4) 4.8.1 There shall be no leakage. permanent distortion or rupture of a valve when an internal pressure of twice the rated working pressure is applied for 5 mm with the sealing assembly open in accordance with 6.6.1. 4.8.2 There shall be no leakage, permanent distortion or rupture of a valve at an internal pressure of twice the rated working pressure applied to the downstream side of the sealing assembly for 5 mm with the upstream end vented in accordance with 6.6. 4.8.3 A valve shall not leak while being subjected to an internal hydrostatic pressure equivalent to a column of water 1,5 m high for 16 h in accordance with 6.6.2.2. 4.9 Non-metallic components (excluding gaskets, seals and other elastomeric parts) (see 6.5 & 6.6) Non-metallic valve parts that may affect proper valve function as defined in this standard shall be subjected to the applicable aging of its non-metallic parts, as described in 6.4 and 6.5, using separate sets of samples, as applicable. After aging, a valve shall meet the requirements of 4.8 and 4.11 when tested in accordance...
Download Address
Download