With more than 30 years of casting history, Wenzhou Longzhu Industrial Co., Ltd. has a large number of experienced casting engineers and technicians. We can produce castings of various sizes, shapes and materials according to the drawings provided by customers, especially in the field of valve castings. Cooperate with Fortune 500 companies for many years.
GS-C251.0619,WCB.WCC,LCB,LCC,LC3,4C,4D,WC6,C5,C12, C12A,CA15，CF3,CF8(-196’C),CF3M,CF8M,CF8C,CD4MCu,CK3MC uN,ZG200-400,ZG230-450,ZG270-500,2G40Cr1,ZG20CrM0.2G15C r1Mo1V,ZG35Cr1MO.ZG16CrMOG(1Cr5Mo),ZG1Cr13,ZGOCr18Ni9 Ti.5A.KmTB Cr26.4A
Resin sand casting, etc.
Sales manager： Mrs.peng E-mail: email@example.com
Tel： 0086-0577-86621768 Fax： 0086-0577-86621935
Address ： No.19 Longyong Road.Xiongxin Village. Longwan,Wenzhou,Zhejiang,China
The safety valve is an important accessory for safety protection of pressure limiting and pressure relief on special equipment (boilers, pressure vessels, pressure pipes, etc.). Safety valves are generally installed directly on special equipment. His design, manufacture, installation, use, inspection, etc. must comply with the requirements of special equipment, because its operational reliability and performance are directly related to equipment and personnel. Safe and closely related to energy conservation and environmental protection.
First, the common safety valves generally have the following types:
1. According to the overall structure and the loading structure, it can be divided into three types: heavy hammer lever type safety valve, spring type safety valve and control type.
2. According to the ratio of the valve opening height to the valve circulation diameter, it can be divided into a micro-open type and a full-open type safety valve.
3. According to the way of safety valve gas discharge, it can be divided into three types: fully enclosed, semi-closed and open.
We mainly use resin sand casting technology, resin sand casting problems analysis from:
Castings are bonded to sand because the coating does not effectively block and isolate, or because the coating reacts with high temperature metal liquids.
1. Poor adhesion of coatings: When sand filling vibrates, the coatings peel off, causing sand sticking of castings.
2. The expansion coefficient of the coating is large: when the coating is in contact with the high temperature metal liquid, the volume expansion of the coating is separated from the casting mould, which results in the sand sticking of the casting.
3. High temperature liquid metals are oxidized by chemical reaction with coatings and moulds to form metal oxides, which have strong adhesion to coatings and moulding sand. They can firmly adhere moulding sand on the surface of castings to form a series of low melting point compounds [in the thick wall and corner of castings, more low melting point materials, and later sand layer). This results in sand adherence of castings. Sometimes, although no sand adherence occurs, it is nevertheless found that sand adherence occurs on the surface of castings. The surface of castings is adhered to a layer of paint which is difficult to remove and produces sticky ash.
Casting sand hole:
1. There are fallen sand in the mould.
2. Coatings with low strength and poor fire resistance can not withstand the erosion of high-temperature metal liquids, and sand is involved in castings.
Casting Blowhole: There are many reasons, the most common one is that there are many substances with large amount of gas in the casting mould, which have fast gas evolution, poor permeability of coatings or sand, and gas is not eliminated in time.