Description

Quick opening closure is a mechanical device used to realize fast opening and closing on special pressure equipment. Because there is no need to tighten or loosen fasteners one by one, the opening and closing time of a quick-opening container is short, and the material handling is quite convenient, so it is widely used in frequent intermittent operations. A quick blind plate is a mechanical device used in the circular opening of pressure vessels and pressure pipelines, widely used in petroleum, chemical, light industry, building materials, and other industries. As one of the important parts of the pressure vessel and pressure pipeline, the quick-opening blind plate is designed for convenience and safety.

Three – flap clamp – type quick – opening blind plate structure

The structure of quick opening closure is varied. Clamp-type quick opening closure is widely used because of its high pressure and ease of use. In the early stage of pipeline construction, two valve clamp type quick opening blind plate was used. Because of the complex structure of the two-valve clamp quick opening closure, is larger in size and gradually eliminated.

After investigation and project approval, a kind of fast-opening blind plate with three flaps clamp type is developed and optimized by the finite element method. It has been proved that the quick opening closure with a three-flap clamp is flexible in opening and closing, convenient in operation, safe, and reliable in use. Three-flap clamp type quick opening closure mainly consists of a head cover, clamp, flange, safety chain device, fast opening mechanism, sealing ring, etc.

Main technical characteristics of three – lobe clamp – type quick – opening closure

(1) Reasonable structure and convenient operation. Compared with the two-flap clamping type quick opening closure, the opening of the three-flap clamping type quick opening closure is small, only one-third or one-fourth of the two-flap clamping type quick opening closure, the swivel arm size is greatly reduced, and only one set of opening and closing mechanism is needed, therefore, the three-flap clamping type quick opening closure is compact in structure and convenient in operation.

(2) Reliable seal. O-type sealing ring self-tightening sealing structure can meet the frequent opening and closing conditions, convenient installation, and disassembly. O sealing ring adopts fluorine rubber integral extrusion to ensure service life.

(3) Safe and reliable use. Three-flap clamp type quick opening closure adopts a mechanical safety interlocking mechanism, which can ensure that the equipment cannot be opened under pressure, and prevent the opening and closing mechanism from losing effect due to the loose lead screw during operation. Safety lock installation adopts a type insertion structure to ensure that only the head cover is closed to the position and the safety lock mechanism is installed

(4)The safety interlocking device can ensure that the head cover is closed in place, and the pressure can be increased only after the safety interlocking mechanism is loaded, otherwise the pressure can not be increased; After pressure discharge, the safety interlocking device must be opened first, and the head cover can only be opened when the pressure in the container is reduced to zero. Otherwise, the head cover cannot be opened. The head cover is not closed in place, and the safety interlocking device cannot be loaded; The head cover cannot be turned after the safety interlock is installed. The device is convenient to manufacture, safe, and reliable.

When it’s opening, the safety interlocking mechanism must be opened first. After pressure relief, the head cover can be opened. Otherwise, the head cover cannot be opened. If the head cover is not closed in place and the clamp is not locked, the safety chain mechanism cannot be loaded, the seal cannot be formed, and pressure cannot be boosted. This device is easy to manufacture, safe, and reliable.

Manufacture of three – lobe clamp – type quick – opening blind plate

(1) The head cover is made of 16Mn Ⅳ grade forging through machining, not casting, so as to avoid trachoma and other defects. According to the size of the shape, the processing sequence and clamping of the inside and outside should be mainly considered. At the same time, a machining allowance of 3m m should be left in the fitting surface of the clamp and flange for finishing after heat treatment.

(2) The clamp is processed by 16Mn Ⅲ grade forging, in the whole

After rough machining and heat treatment, the fitting surface of the head cover and flange can be finished, and the last saw cut into three pieces. For a stirrup with a gauge size larger than ∅1200m m, a three-lobe forging ─ roughing ─ welding ─ finishing ─ milling can be used.

(3) The flange is made of 16Mn Ⅲ grade forging and should be in line with the equipment. The welding end of the cylinder has enough pressure margin, usually choosing the range of 50 ~ 150m according to the different specifications.

(4) The insertion hole of the safety interlock device must be assembled and tested; Open flexible, can realize the lock tight sealing before drilling.

(5) The clip quick-opening mechanism and the lug part should be equipped with the corresponding process pin and process bolt before heat treatment to ensure that the deformation of heat treatment is controlled to the minimum.

Installation of three – lobe clamp – type quick – opening blind plate

After the quick opening closure is assembled and qualified, the groove can be reprocessed and welded with the equipment cylinder. The following problems should be paid attention to:

(1) Welding process evaluation should be made before welding the flange of quick opening closure and the equipment cylinder before installation.

(2) Local heat treatment must be carried out after welding, with 100% ray detection, and hardness check of the weld, hardness is greater than 200HB.

Three-flap clamp type quick opening closure conforms to national standards and industry standards fills the domestic gap, and its performance has reached the international advanced level.

The field use proved that the three-flap clamp type quick opening closure has a reasonable structure, flexible opening, and closing, convenient operation, and safe and reliable use.

Pipeline construction and the maintenance of existing pipelines both need a large number of quick opening closures. Now, pipeline construction is in the great development stage in China, and several oil and gas transmission pipelines are to be built or planned. Therefore, the market prospect of three-valve clamp type quick opening closure is broad.

The head cover, clamp, and flange are the main compression elements. According to the nominal pressure of the three-lobe clamp type quick-opening blind plate, the head cover, clamp, and flange blank are made of Sichuan forging and machined. The quick opening mechanism is mainly composed of left and right rotary trapezoid lead screws and a pair of left and right rotary trapezoid nuts and connecting parts. The quick opening mechanism drives the nut connected with the clamp through positive and reverse rotation of the screw rod so that the clamp does the radial movement to realize opening, closing, and locking. The safety interlocking device adopts the pressure self-tightening structure inserted by the leg type, which can ensure that the equipment cannot be opened under pressure and prevent the opening and closing mechanism from failing due to the loose screw during operation.

Working principle

When closing, move the switch handle on the head cover, tighten the end face of the head cover and the end face of the flange, rotate the lead screw of the quick-opening mechanism in the forward direction, the clamp moves in the radial direction, tights the head cover and flange through the inclined surface, presses the sealing ring, and plays a sealing role.

When opening, first loosen the bolt of the safety interlock device, remove the pressure in the container, and then reverse rotate the screw of the quick-opening mechanism, the clamp makes radial movement outwards, and when the head cover can be opened, move the switch handle on the head cover to open.

quick opening closure