Product features：
Neck mirrors are used in industrial production equipment such as petroleum, chemical, chemical fiber, medicine, food, etc., and can observe the flow reaction of liquid, gas, steam and other media at any time. It is an indispensable accessory to ensure normal production.
Necked sight glass is also called pressure vessel sight glass. The difference between sight glass and conventional equipment is that there is an extra tube at the bottom of the sight glass, which is what we call "neck". Its function is to separate the sealing of the sight glass from the welding port. In this way, the influence of welding stress on the sealing surface of the sight glass is reduced to a minimum. [1] The "neck" of the sight glass with neck is also divided into standard type and non-standard type.
Scope of application
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1. Weakly corrosive materials in chemical and petrochemical production, such as water, ammonia, oil, hydrocarbons, etc.
2. Corrosive materials in chemical production, such as: caustic soda, concentrated sulfuric acid, carbonic acid, acetic acid, ester acid, etc.
3. Low-temperature materials in refrigeration, such as liquid methane, liquid ammonia, liquid oxygen and various refrigerants.
4. Materials with hygiene requirements in the production of light industrial foods and pharmaceuticals, such as beer, beverages, dairy products, grain slurry medical supplies, etc.
technical parameter
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Body material A3 304 304L 316 316L FRP lining
Window material Tempered borosilicate glass Quartz glass
Nut bolt 20# 304 304L 316 316L
Sealing gasket Nitrile rubber gasket Teflon gasket Metal gasket Graphite gasket
Sealing surface Raised surface (RF) Flat surface (FF) Concavo-convex surface (MFM) Tongue and groove surface (TG)
Flange standard HG GB HGJ JB ANSI JIS DIN BS NF
Manufacturing inspection standard HGJ501-502-86
Working temperature Carbon steel: -30℃ ~ +350℃ Stainless steel: -80℃ ~ +480℃
Glass temperature resistance Tempered borosilicate glass: ≤200℃, quartz glass: 1000℃
Glass pressure resistance Toughened borosilicate glass sheet: ≤2.5MPa Quartz glass sheet: ≤2.5MPa
Tempered borosilicate glass cylinder: ≤0.6MPa Quartz glass cylinder: ≤0.6MPa
Allow sudden change temperature <60℃
Appearance Carbon steel: anti-corrosion paint Stainless steel: pickling treatment or anti-corrosion paint
Reference standard
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Standard drawing of HG/T 21620-1986 neck mirror
Chinese name: Standard drawing of mirror with neck (with compilation instructions) [2]
English name:
Classification of Chinese Standard: ICS Classification:
Standard Classification Number: QT Pages: 12
Release date: 1986-12-01 Implementation date: 1987-02-01 Obsolete date:
Replaced standard: Replaced standard:
Reference standard: Adopt standard:
Drafting unit: Equipment Design and Technology Center Station of the Ministry of Chemical Industry Department of Administration: None
Indexing basis: Engineering Section (2010) No. 77
Supplementary revision:
Remark:
Scope: This technical condition is applicable to tempered borosilicate glass used in the standard drawing of HGJ501～5O2-86 pressure vessel sight glasses, with a nominal pressure Pg≤26kgf/cm2 (2.45MPa).