What is a security door
Equipped with anti-theft lock, it can resist abnormal opening under certain conditions within a certain period of time, and has certain security protection performance and meets the corresponding anti-theft security level of the door.
The full name of the anti-theft door is "anti-theft security door". It has both anti-theft and safe performance. According to the "General Technical Requirements for Anti-theft Security Doors", qualified anti-theft doors cannot be pryed open within 15 minutes using chisel, screwdriver, crowbar and other common hand tools and portable electric tools such as hand drills, or a 615 square mm is opened on the door Opening, or a 38 square mm opening in a semicircle of 150 square mm at the locking point.
In addition, the lock used on the anti-theft door must be a special anti-theft door lock with anti-drilling function that has passed the test by the testing center of the Ministry of Public Security. The anti-theft door can be made of different materials, but only the door that meets the standard test qualification and receives the production permit for the security product can be called an anti-theft door.
Door security door classification
1. Classified by security level
According to the anti-theft security level, it is divided into 4 levels, which are A, B, C, and D, from high to low, and then decreasing.
2. Classification by type
There are many types of anti-theft doors in the market today. According to the standard GB25-92 "General Technical Conditions for Anti-theft Security Doors" promulgated by the Ministry of Public Security, anti-theft doors can be divided into three types: fence-type anti-theft doors, physical doors and composite doors.
Fence-style anti-theft door is a common anti-theft door welded by steel pipes in the early days. Its main advantages are ventilation, lightness and relatively low price. The upper part of the anti-theft door is a fence type steel pipe or steel plate, and the lower half is a cold-rolled steel plate, which is locked with multiple lock points to ensure the anti-prying ability of the anti-theft door.
The physical anti-theft door has been widely used in recent years, and is made of laminated cold-rolled steel plates with strong impact resistance. The double-layer steel plate of the door leaf is filled with thermal insulation and fireproof materials, and has the functions of anti-theft, fire prevention, heat insulation and sound insulation. Professional and good writing is in the door industry.
The compound anti-theft door is composed of a physical door and a fence-type anti-theft door.
3. Classification according to structural characteristics
According to the structural characteristics, there are several types of push-pull anti-theft doors, flat-open anti-theft doors and multi-function luxury anti-theft doors. For ordinary consumers, residents' anti-theft security doors are mainly flat-open anti-theft security doors.
The flat-open anti-theft door is further divided into: ordinary flat open door, middle door, son-mother door, double open door and composite door.
A common swing door is a closed door that is opened by a single leaf.
The door in the door has the advantages of a fence door and a flat door. The outer part of the door is a fence door. There is a small door on the fence door. The small door can be used for ventilation and other purposes. .
Son-mother door and double-open door are generally used in homes with large door frames to ensure easy access.
The compound door is also called a frame and two doors, the front door is a fence door, and the rear door is a closed swing door.
Material for making door security door
From the material point of view, the main entrance doors include steel doors, steel-wood combined doors, cast aluminum doors, and copper doors.
1. Steel anti-theft door
Steel anti-theft door is on the one hand because of its hard material; on the other hand it is affordable.
2. Steel-wood combined anti-theft door
Nowadays commonly used in home is this kind of steel-wood anti-theft door, the main reason is that it can choose different colors, wood, lines, patterns according to the decoration style to meet the beautiful effect of matching. The steel-wood anti-theft door is anti-theft through the steel plate in the middle, and the surface is painted or painted.
3. Cast aluminum anti-theft door
Cast aluminum security doors are popular with consumers. Because it is made of aluminum, it does not rust or fade. The cast aluminum door can be divided into three categories: solid wood cast aluminum door, solid core cast aluminum door and plywood cast aluminum door.
4. Copper security door
If the copper security door is used, the market price is too expensive, and it is generally used in luxurious decoration. However, in terms of material, the copper security door is not only fireproof, anticorrosive, dustproof but also anti-prying. But the appearance and color are more rigid.
Introduction:
1,Al2O3 content:min.92%
2.high density, high hardness, high wear resistance
3.widely used in ball mills as abrasive media
With the characters of high mechanical strength, high chemical stability, and excellent heat endurance, inert Alumina Ball can resist high temperature, high pressure, acid, alkali, salt and various organic solvents.
As the material to support and cover catalystin the reactor, inert alumina ball can buffer gas or liquid's flush on catalyst so as to protect catalyst. It also can improve distribution of gas or liquid in the reactor.
Common Alumina ball:
Alumina ball are the simplest, regularly shaped packing, Packed beds consisting of balls have a relatively small surface area per packed volume. Owing to the extremely small void fraction within the packed bed. The pressure drop is relatively high, Balls are frequently used as catalyst carriers and to smooth flows.