Appearance requirements of well cover: no significant welding defects. Check the diameter of the well ring with common tools. The diameter of the operation scope is within the specification of the well cover, with a depth of 40mm. The anchor bolt holes shall be checked one by one with special tooling fixtures. Fit and spray the inspection rubber ring with the well ring. The rubber ring shall be flat in the T-groove, not longer or shorter, firmly bonded, and the fit gap shall not exceed mm. The well cover and well frame shall be assembled flat without shaking and noise, and the height of the cover and frame shall not exceed mm. The O-ring shall be firmly adhered before spraying. The well cover (ring) shall be sprayed evenly without rust.
The color of the surface layer of the nodular cast iron manhole cover shall be consistent with the road color, and the surface layer of the manhole cover shall have raised ground anti-skid lines, and the height width ratio of the protrusion shall be controlled in the middle of 3-8mm. In addition, it can not only reduce the drainage area of the well cover, but also reduce the drainage area. Relative machining and manufacturing methods should be used to solve the problem between the surface of nodular cast iron well cover and well seat. They should have stability when they jump, and they should not touch in the middle. If the well seat support point surface is made of metal materials, the raw materials for noise elimination and shock absorption shall be designed between it and the well cover, and such raw materials shall be reliably connected with the middle of the well cover.
The T-shaped rubber ring shall be matched with the well ring. The rubber ring shall be flat in the T-shaped groove, not longer or shorter, firmly bonded, and the matching gap shall not exceed mm.
The well cover and well frame shall be assembled flat without shaking and noise, and the height of the cover and frame shall not exceed mm.
The T-shaped rubber ring shall be firmly adhered before spraying. The well cover (ring) shall be sprayed evenly without rust.
The quality of nodular cast iron manhole covers is unqualified. Due to various reasons, some fake and inferior manhole covers are used in engineering projects, leaving potential safety hazards for safety. At this stage, in addition to the traditional pig iron manhole covers, nodular cast iron, new concrete and polymer manhole covers are also widely used.