What are the standards and specifications for the installation of plastic-steel windows?

1) The variety, type, specifications, dimensions, opening direction, installation location, connection method, and sealing treatment of plastic doors and windows shall meet the design requirements; the wall thickness of those with reinforced steel interiors and their installation shall comply with the quality requirements of **current finished product standards. (2) The installation of plastic door and window frames, secondary frames, and sashes must be secure. The number and location of the fixing plates or expansion bolts must be correct, and the connection method shall meet the design requirements. The fixing points should be located 150–200 mm away from the window corners, the horizontal mullions, and the vertical mullions, with the distance between fixing points not exceeding 600 mm. (3) The specifications and wall thickness of the reinforcing steel used as an inner lining in the joints of plastic doors and windows must meet the design requirements; the steel members should fit tightly within the cavity of the profiles, and their ends must be firmly fixed to the openings. The window frames must be firmly connected to the mullions, with the spacing between fixing points not exceeding 600 mm. (4) Plastic doors and windows should open and close smoothly, shut tightly, and not bend upwards. Push-and-pull door and window sashes must have anti-fall measures. (5) The models, specifications, and quantities of plastic door and window accessories shall meet the design requirements; they shall be installed firmly, in the correct positions, and their functions shall satisfy the usage requirements. (6) The gaps between plastic door and window frames and the wall should be fully filled with closed-cell elastic material, and the surface should be sealed with sealant. The sealant should adhere firmly, with a smooth, straight surface free of cracks.