How to correctly assemble instrument pipe fittings before use

How to correctly assemble instrument pipe fittings before use
As a kind of pipe fittings, instrument pipe fittings have been widely used in industrial production. However, if it is not correctly installed in use, it will cause the instrument pipe fittings can not work normally, so how should we correctly assemble the instrument pipe fittings before use?
(1) The new parts of instrument pipe fittings also need to be cleaned before assembly.
(2) Lubricate with grease. The grease shall be compatible with metal materials, rubber parts, plastic parts and working medium of instrument fittings. When the working medium is gas, the imported metering pump can use special 221 grease. Apply a thin layer of grease on the surface of the seal installation groove, a thin layer of grease on the rubber seal, and a thin layer of grease on the sealing surface and friction surface of the valve stem.
(3) During the assembly of instrument pipe fittings, it is not allowed to have metal debris, fiber, grease (except those specified for use), dust and other impurities, foreign matter and other pollution, adhere to or stay on the surface of parts or enter the inner cavity of instrument pipe fittings.
(4) The cleaning agent shall be compatible with rubber parts, plastic parts, metal parts and working medium (such as gas) in butt welded tee joint. When the working medium is gas, gasoline (gb484-89) can be used to clean metal parts. Non metallic parts are cleaned with pure water or alcohol.
(5) The decomposed individual parts can be cleaned by immersion. Metal parts with undecomposed non-metal parts can be cleaned with clean and fine silk cloth impregnated with cleaning agent (to avoid fiber falling off and adhering to the parts). When cleaning, remove all grease, dirt, glue, dust, etc. adhering to the wall of instrument pipe fittings.
(6) The non-metallic parts shall be taken out from the cleaning agent immediately after cleaning, and shall not be soaked for a long time.
(7) After cleaning, it needs to be assembled after the washing agent volatilizes (it can be wiped with silk cloth without soaking the cleaning agent), but it should not be put aside for a long time, otherwise it will rust and be polluted by dust.
(8) It should be found out that the pressure of the upstream and downstream pipes of the instrument fittings has been removed before disassembly.
(9) During disassembly and reassembly, care should be taken to prevent damage to the sealing surface of parts, especially non-metallic parts. Special tools should be used when taking out O-rings.
(10) The bolts on the flange shall be tightened symmetrically, step by step and evenly during the assembly of instrument pipe fittings.