How to test and install pipeline full welded ball valve door ( Buried all welded ball valve door)

Pipeline full welded ball valve door ( Buried all welded ball valve door) Before installation should be pressure test to ensure that the valve door rigor and security. 1. All welded ball valve door test: ( 1) Strength test, strength test using water as medium; The valve door on both sides of the sleeves on the welding of high pressure & ndash; Booster to the nominal pressure ball valve door 1. Five times the pressure maintaining 15 min; As a qualified without leakage. ( 2) Leak test: close. some trials using nitrogen as medium; 1 pressure rose to a nominal pressure ball valve door. Insert depth to 1 cm; No air bubbles in the 5 min for qualified. 2. Pipeline full welded ball valve door ( Buried all welded ball valve door) The installation of ( 1) Lifting: should adopt the way of correct lifting valve door, in order to protect the valve rod, don't tie chain hoist in hand wheel, gear box, or actuators. ( 2) Weld quality must conform to the plate bending melting welding joint radiography ( GB3323— 2005). Ⅱ level standard, usually a welding cannot fully guarantee all qualified, so order when the valve door should be required to manufacturer on both ends of the valve gate 1. 0 m long sleeve tube, once the unqualified weld has enough length to unqualified weld mutilation in ball valve and pipe welding and welding, the gate valve should be in 100% full open position, in order to avoid the valve ball is splash damage of welding slag, at the same time ensure that the valve inside the door seal temperature not to exceed 140 degrees Celsius, can take the appropriate cooling measures when necessary.