CN214597746U

CN214597746U - Cleaning assembly and crude oil filter element cleaning device

Info

Publication number: CN214597746U
Application number: CN202120384692.XU
Authority: CN
Inventors: 张殿龙; 宋家喜; 王刚; 王峰; 王建宁; 骆世杰; 鄢仁生; 顾明; 刘敏达; 樊保锋; 文伟; 张宝金; 杨瑞; 张雷; 侯广典; 赵文
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-02-20
Filing date: 2021-02-20
Publication date: 2021-11-05
Anticipated expiration: 2031-02-20

Abstract

The utility model provides a wash subassembly and crude oil filter core belt cleaning device relates to crude oil processing equipment technical field, has solved the technical problem that current crude oil filter core clearance mode is inefficiency. The cleaning assembly comprises a fixing mechanism and a spraying mechanism, the fixing mechanism is detachably connected with the filter element, the spraying mechanism comprises an outer spraying nozzle and/or an inner spraying nozzle which can spray high-pressure cleaning liquid, and the outer spraying nozzle is positioned at the periphery of the fixing mechanism and used for spraying and cleaning the outer wall of the filter element; the inner spray nozzle extends into the filter element positioned on the fixing mechanism and is used for spraying and washing the inner wall of the filter element. The device can be dismantled the back with crude oil filter core and connect on fixed establishment, sprays the high-pressure washing liquid that the mouth erupted through being located the inside interior spray nozzle of filter core outlying outer spray nozzle and/or stretching into the filter core, sprays filter core outer wall and/or inner wall, can wash the filter core with high efficiency, saves the labour, practices thrift the cost, can effectually guarantee the repetitious usage of filter core, and safe and reliable does not harm the filter core.

Description

Cleaning assembly and crude oil filter element cleaning device

Technical Field

The utility model belongs to the technical field of crude oil processing equipment technique and specifically relates to a wash subassembly and crude oil filter core belt cleaning device is related to.

Background

The crude oil pipeline filter is one of very important equipment in the crude oil gathering and transporting process, plays a very important protective action on the normal operation of an oil transportation pump, and has the characteristics of simple structure, convenience in disassembly, large using amount and the like.

The applicant has found that the prior art has at least the following technical problems: the existing crude oil filter element has high cleaning difficulty and does not have special cleaning equipment. At present, in field actual work, filter element cleaning work usually adopts original methods such as burning, beating, and the like, so that a filter screen is easy to damage, short in service life and frequent in replacement, the workload of workers is increased, the operation cost is increased, and the cleaning efficiency is low.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a cleaning component and a cleaning device for a filter element of a crude oil filter, which solve the technical problem that the cleaning mode of the filter element of the crude oil filter in the prior art is low in efficiency; the utility model provides a plurality of technical effects that preferred technical scheme among a great deal of technical scheme can produce see the explanation below in detail.

In order to achieve the above purpose, the utility model provides a following technical scheme:

the utility model provides a pair of wash subassembly, include fixed establishment and spray the mechanism, wherein:

the fixed mechanism is detachably connected with the filter element, the spraying mechanism comprises an outer spraying nozzle and/or an inner spraying nozzle which can spray high-pressure cleaning liquid, and the outer spraying nozzle is positioned at the periphery of the fixed mechanism and is used for spraying and washing the outer wall of the filter element; the inner spray nozzle extends into the filter element on the fixing mechanism and is used for spraying and washing the inner wall of the filter element.

Preferably, more than two groups of the outer spraying nozzles are arranged, and the outer spraying nozzles of all the groups are arranged around the central axis of the filter element on the fixing mechanism; and each group of the outer spray nozzles are arranged along the extension direction of the filter element.

Preferably, the inner spray nozzle comprises a spray pipe and a spray hole, wherein:

the spray pipe and the filter element positioned at the periphery of the spray pipe are coaxially arranged, and the spray holes are densely distributed on the peripheral wall of the spray pipe to form a plurality of high-pressure cleaning liquid flows sprayed to the inner wall of the filter element.

Preferably, the cleaning assembly further comprises an inlet manifold and a bypass line, wherein:

the liquid inlet main pipe is arranged around the outer spraying nozzles of all the groups at intervals, the shunt pipes are communicated with the liquid inlet main pipe, and each shunt pipe is respectively communicated with the outer spraying nozzles in each group; the inner spray nozzle is connected with the liquid inlet main pipe or any one of the shunt pipes or any one of the outer spray nozzles through a drainage pipe.

Preferably, the fixing mechanism comprises a pneumatic chuck connected with an air source, and clamping jaws on the pneumatic chuck move radially to detachably fix or release the filter element.

Preferably, fixed establishment still includes drive arrangement, drive arrangement with the air chuck drive is connected, drive arrangement can forward rotation and counter-rotation be used for driving and be located on the air chuck the filter core is according to the set angle horizontal hunting.

The utility model also provides a crude oil filter core belt cleaning device, including staving and the above-mentioned subassembly that washs, the outer mouth that sprays is located on the staving inner wall, fixed establishment reaches the interior mouth that sprays is located in the staving.

Preferably, a liquid outlet is formed in the bottom of the barrel body, and a pipeline is connected to the liquid outlet and used for draining dirty liquid out of the barrel body;

the upper portion of staving is provided with the gas circuit mouth that is used for the air supply pipe to pass, trachea and air supply intercommunication, the trachea by the gas circuit mouth stretches into in the staving and with the fixed establishment intercommunication do fixed establishment provides air supply drive power.

Preferably, the barrel body comprises a barrel body and a cover body for sealing the barrel body, a support frame is arranged at the lower part of the barrel body, and a movable wheel body is arranged at the bottom of the support frame.

Preferably, the barrel body includes a barrel body and a cover body, the barrel body is provided with a locking mechanism for locking the cover body on the barrel body, the locking mechanism includes a butt rod and a locking bolt, wherein:

the first side of the abutting rod is hinged with the barrel body, and the cover body is connected to the position, facing the barrel body, of the abutting rod; the second side of the butt rod, which is opposite to the first side, is provided with an inner thread groove, the position of the barrel body, which corresponds to the second side of the butt rod, is provided with a connecting block for the locking bolt to pass through, and the locking bolt passing through the inner thread groove and the connecting block is screwed, so that the cover body covering the barrel body is clamped between the barrel body and the butt rod.

Compared with the prior art, the utility model, following beneficial effect has:

1. the utility model provides a wash the subassembly, can dismantle the back with crude oil filter core and connect on fixed establishment, spray the high-pressure cleaning liquid that the mouth erupted through being located the inside interior spray nozzle of filter core outlying outer spray nozzle and/or stretching into the filter core, spray filter core outer wall and/or the inner wall of connecting on fixed establishment, can comparatively high-efficiently wash crude oil filter core, save the labour, practice thrift the cost, can effectual repetitious usage who guarantees the filter core, safe and reliable does not harm the filter core.

2. The utility model provides a crude oil filter core belt cleaning device sets up to the structure of staving, will wash the subassembly setting in the staving, carries out the jetter to the filter core of connecting in the staving through fixed establishment, prevents that the foul solution from flowing to the cleaning site, when effectively wasing the filter core, guarantees to wash on-the-spot environmental protection health.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic diagram of a crude oil filter cartridge cleaning apparatus having the cleaning assembly described above;

FIG. 2 is a first perspective side view of a crude oil filter cartridge cleaning apparatus;

FIG. 3 is a second perspective side view of the crude oil filter cartridge cleaning apparatus;

FIG. 4 is a schematic cross-sectional view taken along line A-A of FIG. 3;

FIG. 5 is a schematic view of the filter cartridge secured to the air chuck;

FIG. 6 is a schematic diagram of a prior art air chuck;

FIG. 7 is a schematic view of the internal structure of the crude oil filter cartridge cleaning apparatus having the above-described cleaning assembly;

fig. 8 is a schematic view of the overall external configuration of the crude oil filter cartridge cleaning apparatus having the above-described cleaning assembly.

In the figure 1, an outer spray nozzle; 2. an inner spray nozzle; 21. a drainage tube; 3. a filter element; 41. a pneumatic chuck; 411. a clamping jaw; 42. a rotating cylinder; 43. a gas source connector; 44. a first control valve; 45. a second control valve; 51. a shunt tube; 52. a liquid inlet header pipe; 61. a barrel body; 611. a liquid outlet; 612. a gas crossing; 62. a cover body; 7. a support frame; 8. a wheel body; 91. a butting rod; 92. locking the bolt; 911. an internal thread groove; 93. and (4) connecting the blocks.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. It is to be understood that the embodiments described are only some embodiments of the invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "length", "width", "height", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "side", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

The embodiment of the utility model provides a spray assembly and crude oil filter core belt cleaning device that can effectively carry out effective spray rinsing to crude oil filter core.

The technical solution provided by the present invention is explained in more detail with reference to fig. 1 to 8.

Example 1

As shown in fig. 1-8, the present embodiment provides a cleaning assembly comprising a fixing mechanism and a spraying mechanism, wherein: the fixing mechanism is detachably connected with the filter element 3, the spraying mechanism comprises an outer spraying nozzle 1 and/or an inner spraying nozzle 2 which can spray high-pressure cleaning liquid, and the outer spraying nozzle 1 is positioned at the periphery of the fixing mechanism and is used for spraying and cleaning the outer wall of the filter element 3; the inner spray nozzle 2 extends into the filter element 3 on the fixing mechanism and is used for spraying and washing the inner wall of the filter element 3.

In order to improve the cleaning effect of the filter element 3, referring to fig. 1-4, the spraying mechanism in the embodiment includes an outer spraying nozzle 1 and an inner spraying nozzle 2 which can spray high-pressure cleaning liquid, wherein the outer spraying nozzle 1 is located at the periphery of the fixing mechanism and is used for spraying and cleaning the outer wall of the filter element 3; the inner spray nozzle 2 extends into the filter element 3 on the fixing mechanism and is used for spraying and washing the inner wall of the filter element 3. The cleaning assembly in the embodiment can carry out high-pressure spray cleaning on the inner wall and the outer wall of the filter element 3, improve the cleaning effect on the filter element 3 and prevent crude oil residue.

Wherein, the cleaning solution is hot water or an oil removing agent solution, and the oil removing agent solution is preferably selected.

As an alternative embodiment, referring to fig. 1 and 8, the outer spray nozzles 1 are arranged to form more than two groups, and the outer spray nozzles 1 of all the groups are arranged around the central axis of the filter element 3 on the fixing mechanism; every group sprays mouth 1 outward and all arranges along 3 extending direction of filter core, and every group sprays the extension length that the group equals or is greater than the length of filter core 3 outward, guarantees effectively spraying of filter core 3, prevents to spray not in place to 3 local of filter core.

Specifically, referring to fig. 1 and 8, the outer spray nozzles 1 in the present embodiment are provided with three or four groups at intervals, and referring to fig. 7, the outer spray nozzles 1 in fig. 7 include three groups arranged at even intervals. When the spraying assembly is disposed in the tub, the outer spraying nozzle 1 may be fixed to an inner wall of the tub body 61. The outer spraying nozzle 1 and the filter element 3 are arranged at intervals, so that the outer wall of the filter element 3 can be effectively sprayed.

As an alternative embodiment, see fig. 4, the inner spray nozzle 2 comprises a spray pipe and spray holes, wherein: the spray pipe and the filter element 3 positioned at the periphery of the spray pipe are coaxially arranged, and the spray holes are densely distributed on the peripheral wall of the spray pipe at intervals to form a plurality of high-pressure cleaning liquid flows sprayed to the inner wall of the filter element 3; can evenly spray the inner wall of the filter element 3 connected on the fixing mechanism. The spray holes are uniformly arranged on the peripheral wall of the spray pipe, and the cleaning liquid is further pressurized due to the small aperture of the spray holes, so that high-pressure cleaning liquid flow is formed.

Wherein, referring to fig. 3, when the filter element 3 is connected to the fixing mechanism, the inner spraying group can also be arranged on the fixing mechanism and positioned in the filter element 3; or, when filter core 3 is connected on fixed establishment, interior spray nozzle 2 and fixed establishment do not connect, and interior spray nozzle 2 is fixed on the staving and is served relative with fixed establishment, and fixes in the interior spray nozzle 2 of staving one end can extend to filter core 3, carries out the spray rinsing to 3 inner walls of filter core.

As an alternative embodiment, referring to fig. 3 and 8, the cleaning assembly further comprises an inlet manifold 52 and a bypass 51, wherein: the main liquid inlet pipe 52 is arranged around all the groups of the outer spray nozzles 1 at intervals, and when the cleaning assembly is arranged on the barrel body, the main liquid inlet pipe 52 is arranged around the outer wall of the barrel body; the shunt pipe 51 is communicated with the liquid inlet header pipe 52, and particularly, the shunt pipe 51 and the liquid inlet header pipe can be communicated through a joint; and each shunt tube 51 is respectively communicated with the outer spray nozzles 1 in each group; the inner spray nozzle 2 is connected with the inlet main pipe 52 or any shunt pipe 51 or any outer spray nozzle 1 through the draft tube 21.

Referring to fig. 7, in the embodiment, one of the outer spray nozzles 1 is connected with a drainage tube 21, and a quick connector for connecting with the spray tube of the inner spray nozzle 2 is arranged at the end of the drainage tube 21; of course, the inner spray nozzle 2 in this embodiment can also be connected to the inlet main pipe 52 or any of the branch pipes 51 through a draft tube.

The inlet manifold 52 is connected to a cleaning liquid storage device, and a pump body (not shown) is interposed therebetween. And when the pump body is opened, the cleaning liquid can enter the liquid inlet main pipe 52 under certain pressure under the action of the pump body and is distributed to different outer spray nozzles 1 through the shunt pipe 51 to be sprayed out, so that the outer wall of the filter element 3 is cleaned. Referring to fig. 7, the cleaning liquid in the outer spray nozzle 1 enters the spray pipe of the inner spray nozzle 2 through the drainage pipe, and is sprayed out through the spray holes on the peripheral wall to spray and clean the inner wall of the filter element 3.

As an alternative, referring to fig. 4-6, the fixing mechanism in this embodiment comprises an air chuck 41 connected with an air source, and the clamping jaws 411 on the air chuck 41 are radially moved for detachably fixing or releasing the filter cartridge 3. The air chuck 41 is a conventional mature technology, and is shown in fig. 6, and fig. 6 is a schematic structural diagram of the air chuck 41 in the prior art, and the specific structure of the air chuck 41 is not described herein and can be directly purchased from the market. The air chuck 41 may be disposed inside the tub by a chuck. Air chuck 41 can be connected with the air supply, and the air supply is provided with the air supply in to air chuck 41, and air supply pressure makes three clamping jaw 411 radial movement, when three clamping jaw 411 was close to mutually, can be fixed with filter core 3, when three clamping jaw 411 kept away from mutually, can release filter core 3 that the washing was accomplished convenient to use.

As an alternative embodiment, referring to fig. 2 to 5, the fixing mechanism further includes a driving device, the driving device is drivingly connected to the air chuck 41, and the driving device can rotate in a forward direction and rotate in a reverse direction for driving the filter element 3 located on the air chuck 41 to swing left and right at a set angle. In the present embodiment, the driving device is specifically a rotary cylinder 42 or a motor connected with a speed reducer. The rotary cylinder 42 is in driving connection with the air chuck 41 through a rotary shaft, and can be used for setting the rotation angle of the rotary cylinder 42, if the rotary cylinder 42 swings 120 degrees in the forward direction (not limited to the angle, and can be set according to actual conditions), and swings 120 degrees in the reverse direction again, so that the filter element 3 positioned on the air chuck 41 swings 120 degrees in the forward direction and swings 120 degrees in the reverse direction again, and the outer spray nozzle 1 positioned outside the filter element 3 and the inner spray nozzle 2 positioned inside the filter element 3 can be conveniently and fully sprayed on the filter element 3. The swing angle of the rotary cylinder 42 is set to a conventional setting in the art, such as setting a controller connected to a power supply of the rotary cylinder 42, and the controller connected to a touch display screen for inputting control commands, for receiving the input commands and controlling the movement of the rotary cylinder 42.

Example 2

Referring to fig. 1, 7 and 8, the embodiment provides a cleaning device for a crude oil filter element, which includes a barrel body and the cleaning assembly, wherein an outer spray nozzle 1 is located on the inner wall of the barrel body, and a fixing mechanism and an inner spray nozzle 2 are located in the barrel body. The inlet manifold 52 is located at the periphery of the barrel body, and the water distribution manifold is located in the barrel body or outside the barrel body.

The crude oil filter element cleaning device of this embodiment sets up to the structure of staving, will wash the subassembly setting in the staving, to connecting filter core 3 in the staving through fixed establishment spray rinsing, high-pressure cleaning liquid stream sprays in the staving, and the foul solution after wasing is located the staving, prevents that the foul solution from flowing to the cleaning site, when effectively wasing filter core 3, guarantees to wash on-the-spot environmental protection health.

As an alternative embodiment, referring to fig. 7, a liquid outlet 611 is disposed at the bottom of the barrel, and a pipeline is connected to the liquid outlet 611 for draining the dirty liquid to the outside of the barrel; be convenient for concentrate on handle, discharge the foul solution, prevent that the foul solution from gathering to influence the washing to filter core 3 in the staving, prevent simultaneously that the foul solution from directly discharging to the cleaning field, influencing the health.

Referring to fig. 7, the upper portion of the barrel body is provided with an air passage opening through which an air supply pipe passes, the air pipe is communicated with an air source, and the air pipe extends into the barrel body from the air passage opening and is communicated with the fixing mechanism to provide air source driving force for the fixing mechanism. Referring to fig. 7, the air source in this embodiment is connected to an air source connector 43 through an air path, the air source connector 43 is connected to a first control valve 44 for controlling the movement of the starting chuck upper jaw 411 through an air path, and the air source is connected to a second control valve 45 for controlling the rotation of the rotary cylinder 42 through an air path, wherein the connection manner of the air path and the first control valve and the second control valve are conventional, the air path is not shown in fig. 7, and the air path led out from the first control valve 44 and the second control valve 45 extends into the barrel body through an air path port 612 to be communicated with the pneumatic chuck 41 and the rotary cylinder 42; the structure prevents the pipeline from influencing the cleaning of the filter element 3 in the barrel body.

As an alternative embodiment, as shown in fig. 1 and 8, the barrel body includes a barrel body 61 and a cover 62 for covering the barrel body 61, the support frame 7 is disposed at the lower portion of the barrel body 61, and the movable wheel 8 is disposed at the bottom of the support frame 7.

The matching structure of the wheel body 8 and the supporting frame 7 is convenient to move and use. The split structure that lid 62 and bucket body 61 constitute is convenient for the operator to open the staving, will treat abluent filter core 3 to be connected to fixed establishment on.

As an alternative embodiment, as shown in fig. 1 and 8, the barrel body includes a barrel body 61 and a cover 62, a locking mechanism for locking the cover 62 to the barrel body 61 in a sealing manner is disposed on the barrel body 61, and the locking mechanism can connect the cover 62 and the barrel body 61 and facilitate opening the cover 62.

Specifically, referring to fig. 8, an embodiment of a locking mechanism is provided in the present embodiment, the locking mechanism includes an abutting rod 91 and a locking bolt 92, wherein: the first side of the abutting rod 91 is hinged with the barrel body 61, and the cover body 62 is connected to the position of the abutting rod 91 facing the barrel body 61; the second side of the abutting rod 91 opposite to the first side is provided with an inner thread groove 911, a connecting block 93 for the locking bolt 92 to pass through is arranged at a position of the barrel body 61 corresponding to the second side of the abutting rod 91, and the locking bolt 92 passing through the inner thread groove 911 and the connecting block 93 is screwed, so that the cover body 62 which is sealed and fitted on the barrel body 61 can be clamped between the barrel body 61 and the abutting rod 91.

When the filter element cleaning device is used specifically, the locking bolt 92 is loosened to separate the locking bolt 92 from the connecting block 93, the cover body 62 can be opened at the moment, and an operator fixes the filter element 3 to be cleaned on the starting chuck; the lid 62 is closed, the lock bolt 92 is tightened, and the lid 62 is engaged between the tub body 61 and the abutment lever 91 by the lock bolt 92, thereby preventing the lid 62 from falling. And starting a pump body connected with the liquid inlet main pipe 52, and enabling cleaning liquid to enter the outer spray nozzle 1 and the inner spray nozzle 2 to respectively perform high-pressure spray washing on the outer wall and the inner wall of the filter element 3. The flow rate of the cleaning liquid can be adjusted by adjusting the power of the pump body or a flow regulating valve connected to the liquid inlet manifold 52.

The cleaning device for the crude oil filter element 3 in the embodiment is used for cleaning the crude oil filter element 3, realizes the mechanization of crude oil filter consideration cleaning, reduces the workload and the labor intensity of workers, improves the labor environment, improves the safety and the environmental protection coefficient, and saves the cost. And has the following characteristics:

1. the volume is small, the weight is light, and the movement is convenient;

2. the cleaning site is environment-friendly and sanitary;

3. labor force is saved, cost is saved, and the filter element 3 can be effectively used for multiple times;

4. the fire is not moved, the safety and the reliability are realized, and the filter element 3 is not damaged;

5. the size of the cleaning liquid can be manually adjusted.

The particular features, structures, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. The utility model provides a cleaning assembly which characterized in that, includes fixed establishment and sprays the mechanism, wherein:

2. The cleaning assembly of claim 1, wherein the outer spray nozzles are arranged in more than two groups, and the outer spray nozzles of all the groups are arranged around a central axis of the filter element on the fixing mechanism; and each group of the outer spray nozzles are arranged along the extension direction of the filter element.

3. The cleaning assembly of claim 1, wherein the inner spray nozzle comprises a spray tube and a spray aperture, wherein:

4. The cleaning assembly of any one of claims 1-3, further comprising an inlet manifold and a bypass line, wherein:

5. The cleaning assembly of any one of claims 1-3, wherein the securing mechanism comprises a pneumatic chuck having a gas source connected thereto, and wherein jaws on the pneumatic chuck are radially movable for removably securing or releasing the filter element.

6. The cleaning assembly of claim 5, wherein the fixing mechanism further comprises a driving device, the driving device is drivingly connected to the air chuck, and the driving device can rotate in a forward direction and rotate in a reverse direction to drive the filter element on the air chuck to swing left and right according to a set angle.

7. A cleaning device for a filter element of a crude oil filter, which is characterized by comprising a barrel body and the cleaning assembly as claimed in any one of claims 1 to 6, wherein the outer spray nozzle is positioned on the inner wall of the barrel body, and the fixing mechanism and the inner spray nozzle are positioned in the barrel body.

8. The crude oil filter element cleaning device according to claim 7, wherein a liquid outlet is arranged at the bottom of the barrel body, and a pipeline is connected to the liquid outlet and used for guiding dirty liquid out of the barrel body;

9. The cleaning device for the crude oil filter element as claimed in claim 7 or 8, wherein the barrel body comprises a barrel body and a cover body for sealing the barrel body, a support frame is arranged at the lower part of the barrel body, and a movable wheel body is arranged at the bottom of the support frame.

10. The crude oil filter cartridge cleaning device of claim 7 or 8, wherein the barrel body comprises a barrel body and a cover body, a locking mechanism for locking the cover body on the barrel body is arranged on the barrel body, the locking mechanism comprises a butt rod and a locking bolt, wherein: