Safety valve installation of quality testing requirements. The test item are as follows: alloy steel components, spectral analysis materials without error use; between disc and seat joints is non-pitting, grooves, using red ink check and 100% good connection; parts machining accuracy, comply with documentation requirements for equipment and technology ; alloy steel bolt hardness test, meet the material performance requirements; body appearance is without trachoma, crack defects; valve spring appearance is free of cracks, delamination, surface and spring at both ends of the vertical center line, its material and dimensions meet the technical documentation requirements; high, medium pressure and large-scale manufacturers should provide a safety valve of its spring characteristic curve; stem curvature should be