Gu Chang-year foundry with you introduce technical standards ductile manhole cover:. A ductile iron Manhole covers material diameter sealing range of plus or minus 2 mm, height Manhole covers and with an accuracy of plus or minus 1 mm Which covers casting , with the gap of 3 mm. b. Manhole covers tensile strength greater than 500N / mm, hardness standards HB190-230. Covers pressure to meet the Ministry of Construction CJ / T3012-93 "cast iron manhole covers," the industry standard, heavy covers pressure 360KN, light covers 210KN. cT rubber ring EPDM rubber covers much money casting, performance indicators heavy national standard GB-7529-87. d. anti-theft feature is well connected by a fixed shaft and seat covers covers casting, on the other side with a pin fixed this method to complete, with a strong anti-theft and anti-cavitation erosion. Ductile iron covers inspection: in strict accordance with test standards. 1. Appearance: No obvious casting defects, the pattern is clear, clear handwriting. 2. Roughness test: with special mold inspection covers flatness. Making a diameter of product size, depth 37mm tire with the size of the processing by machine, tire covers on the covers with Caster, there can shake and sound, covers no more than mold, depth (37mm) with gap 3mm. 3. bearing loads using sampling methods. In the press do test pressure test, covers pressure 360KN 210KN confirm eligibility or batch. Gu Chang foundry specializing in the production of ductile iron manhole covers, are used in various places, welcome to buy! How much covers casting | Xinjiang covers casting | Chang in foundry provided by Gu Chang in foundry. Gu Chang-year foundry (www.sxcnzz.com) strong, credible, in Jinzhong machining industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead Chang and you work in the foundry into the brilliant, for a better future!