JP6848515B2 - Water-stop structure for sealed water piping - Google Patents

Description

The present invention relates to a water blocking structure for a sealing water pipe.

Generally, in equipment used in plants (pumps, agitators of autoclaves, etc.), if you do not like the leakage of gas or liquid in the process, or if the pressure inside the equipment is high, a mechanical seal is used for the shaft seal of the rotating equipment. Will be done. Further, in the mechanical seal, water (hereinafter referred to as "seal water") is used as a seal medium so as to contribute to lubrication and cooling of the seal surface and prevent gas or liquid in the device from leaking to the outside (hereinafter referred to as "seal water"). For example, Patent Document 1).

There are various types of mechanical seals that use seal water. For example, (1) a type that discharges the seal water from the inlet to the outlet of the mechanical seal, and (2) a reuse type that returns the seal water that enters from the inlet of the mechanical seal and exits to the inlet and circulates it. , (3) There are various types such as a type in which a constant pressure is applied to the inlet side of the mechanical seal to hold the seal water in the shaft seal portion.

For both types of mechanical seals, the pressure of the seal water must be kept higher than the operating pressure inside the equipment to prevent leakage of gas or liquid inside the equipment. In addition, it is necessary to maintain the pressure of the sealing water at a specified level at all times during the operation of the equipment. If the pressure of the sealing water deviates from the specified level, the mechanical seal may be damaged due to a decrease in the lubricity of the sealing surface or a decrease in the cooling effect. As a result, the gas or liquid in the device may leak to the outside, making the device inoperable. In addition, if the liquid or gas inside the device leaks to the outside, it may affect the surrounding environment.

Therefore, if it becomes difficult to maintain the pressure of the seal water at the specified level for some reason, it is necessary to temporarily stop the operation of the equipment and perform repairs such as replacement of the mechanical seal. In addition, even if water leaks from the piping used to supply the sealing water to the mechanical seal (hereinafter referred to as "sealing water piping") for some reason, the pressure of the sealing water can be maintained at the specified level. Since it becomes difficult, it is necessary to temporarily stop the operation of the equipment and perform repairs such as replacement of the sealing water pipe in the same manner as described above.

As a repair method when the fluid flowing inside leaks from the piping of a power plant, a chemical plant, etc., there is a method of extracting the internal fluid, drying the leaked part, and then repairing it with a filler or an adhesive (for example, Patent Documents). 2).

Japanese Unexamined Patent Publication No. 2015-129444 Japanese Unexamined Patent Publication No. 2006-329249

However, in the technique described in Patent Document 2, it is necessary to stop the operation of the equipment in order to repair after extracting the fluid in the pipe. On the other hand, in a continuously operating plant, if the operation of the equipment used therein is stopped, the operating rate and productivity of the equipment will decrease.

Therefore, an object of the present invention is to provide a technique capable of repairing a water leak in a sealing water pipe without stopping the operation of a device using a mechanical seal on the shaft sealing portion.

One aspect of the present invention is
It is a water-stop structure for the seal water pipe that stops water leaks that occur in the seal water pipe for supplying seal water to the mechanical seal.
A first sheet arranged so as to cover the leaked portion of the sealed water pipe, and
A second sheet arranged outside the first sheet and
A third sheet arranged outside the second sheet and
A clamp for pressing the first sheet against the leaked portion of the sealing water pipe via the second sheet and the third sheet is provided.
The first sheet has a higher pressure resistance than the second sheet.
The second sheet has higher elasticity than the first sheet.
The third sheet has a water-stop structure for a sealing water pipe having a higher rigidity than the second sheet.

According to the present invention, it is possible to repair a water leak in a sealing water pipe without stopping the operation of a device using a mechanical seal on the shaft sealing portion.

It is sectional drawing of the main part which shows the structural example of the water stop structure of the seal water pipe which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the embodiment of the present invention, the description will be given in the following order.
1. 1. Inventor's findings 2. Water-stop structure for sealing water piping 3. How to stop the sealing water piping 4. Effect of embodiment 5. Deformation example etc.

<1. Inventor's findings>
The seal water pipe for supplying the seal water to the mechanical seal includes a pipe connected to the inlet of the mechanical seal and a pipe connected to the outlet of the mechanical seal. Each pipe is supported by a metal fitting called a pipe support. Equipment such as pumps that use mechanical seals vibrate during operation, which causes the piping support and piping to rub against each other. As a result, a part of the pipe is rubbed and thinned, and pinholes may occur. When a pinhole is generated in the pipe, the seal water leaks from the pinhole, so that the pressure of the seal water flowing through the seal water pipe is reduced. As a result, it becomes difficult to maintain the pressure of the sealing water at a specified level. At that time, if the operation of the equipment is temporarily stopped and then the piping is replaced or repaired, the operating rate and productivity of the equipment are lowered.

Therefore, the present inventor tries to repair the water leak without stopping the operation of the device when a hole such as a pin hole is formed in the seal water pipe of the mechanical seal and a water leak occurs from the hole as follows. Water stop treatment was applied. First, a rubber sheet was pressed against the seal water pipe to close the pinhole, and then the seal water pipe and the rubber sheet were clamped. As a result, the seal water did not leak from the seal water pipe.

However, about several tens of minutes after the above water stop treatment was applied, the seal water gradually leaked from the seal water pipe. Therefore, the present inventor investigated the cause of the recurrence of the water leak. As a result, it was found that the rubber sheet had holes and water leaked. In addition, if the thickness of the rubber sheet used is increased, or if multiple rubber sheets are used in layers, the period from repair to recurrence of water leakage will be extended, but in either case, the final result. It was found that the rubber sheet had holes in it.

Based on these findings, the present inventor can repair water leaks in the sealing water piping without stopping the operation of the device using the mechanical seal on the shaft seal, and the repaired water. The present invention has been completed by diligently studying a water blocking structure capable of effectively suppressing the recurrence of leakage.

<2. Water-stop structure for sealing water piping ＞
FIG. 1 is a schematic cross-sectional view of a main part showing a configuration example of a water blocking structure of a sealing water pipe according to an embodiment of the present invention.

The illustrated water stop structure is a structure for stopping water at a water leakage point 2 such as a pinhole generated in the seal water pipe 1, and is a structure for stopping water from the first sheet 11, the second sheet 12, and the third sheet 13. And a clamp 14.

(Piping for sealed water)
The seal water pipe 1 is a pipe having a circular cross section. The seal water supplied to the mechanical seal flows inside the seal water pipe 1. The pressure of the seal water flowing in the seal water pipe 1 is maintained at a pressure higher than the pressure inside the equipment in order to prevent gas leakage and liquid leakage of the equipment using the mechanical seal. Specifically, the pressure of the sealing water is maintained at a very high pressure level of several to ten and several times that of the water pressure of general tap water. Therefore, metal is used as the material of the sealing water pipe 1.

The water-stopping structure according to the present embodiment is preferably applied to water-stopping the seal water pipe 1 having a nominal diameter of 3/8 inch or more and 1 inch or less. Further, the water blocking structure according to the present embodiment is applied when the internal pressure of the pipe (pressure of the sealing water) is very high as in the sealing water pipe 1, preferably when it is 1000 KPaG or more and 7000 KPaG or less.

(1st sheet)
The first sheet 11 is arranged so as to cover the water leakage portion 2 of the seal water pipe 1. The first sheet 11 is attached so as to be in direct contact with the outer peripheral surface of the sealing water pipe 1. Further, the first sheet 11 is bent in a curved shape (C shape) along the outer peripheral surface of the sealing water pipe 1.

The first sheet 11 is composed of a sheet having a higher pressure resistance than the second sheet 12. The first sheet 11 is preferably composed of a fluororesin sheet. The fluororesin sheet is excellent in tensile strength, elongation, and impact strength in addition to pressure resistance. Therefore, if the first sheet 11 is made of a fluororesin sheet, even if the first sheet 11 is pushed by the high-pressure sealing water flowing in the sealing water pipe 1 at the water leakage point 2, the sheet is less likely to have a hole. Further, the fluororesin sheet can be bent in a curved shape along the outer peripheral surface of the sealing water pipe 1. By the way, when the first sheet 11 is composed of a resin sheet other than the fluororesin sheet (for example, a non-asbestos type gasket sheet), the sheet cracks when the sheet is bent along the outer peripheral surface of the sealing water pipe 1. May enter. Further, even if the sheet is not cracked, there is a risk that the sheet will be punctured by being pushed by the high-pressure sealing water.

The thickness dimension of the fluororesin sheet is preferably 2 mm or more and 4 mm or less for the following reasons. If the thickness of the fluororesin sheet is less than 2 mm, the sheet may be punctured by being pushed by high-pressure sealing water. If the thickness of the fluororesin sheet exceeds 4 mm, the sheet may be cracked when the sheet is bent along the outer peripheral surface of the sealing water pipe 1.

Examples of the fluororesin sheet include PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer), FEP (tetrafluoroethylene / hexafluoropropylene copolymer), and ETFE (tetrafluoroethylene / tetrafluoroethylene / Sheets such as ethylene copolymer), PVDF (polyvinylidene fluoride), PCTFE (polychlorotrifluoroethylene), and ECTFE (chlorotrifluoroethylene / ethylene copolymer) can be used.

(2nd sheet)
The second sheet 12 is arranged outside the first sheet 11. In the present embodiment, in the diameter direction of the seal water pipe 1, the side closer to the center of the seal water pipe 1 is the inside, and the side far from the center of the seal water pipe 1 is the outside. The second sheet 12 is attached so as to be in close contact with the first sheet 11. Further, the second sheet 12 is bent in a curved shape in the same manner as the first sheet 11.

The second sheet 12 is composed of a sheet having higher elasticity than the first sheet 11. "Elasticity" described here is synonymous with "elasticity". The second sheet 12 is preferably composed of a rubber sheet. The rubber sheet is superior in flexibility to the first sheet 11 made of a fluororesin sheet. Therefore, when the second sheet 12 is sandwiched between the first sheet 11 and the third sheet 13 and pressed by the clamp 14, the adhesion between the first sheet 11 and the third sheet 13 is maintained. The second sheet 12 can function as an enhancing adhesive sheet. Further, by interposing the second sheet 12, the tightening force of the clamp 14 can be efficiently transmitted to the first sheet 11. The above-mentioned "adhesion" refers to a mode in which a gap does not occur between the first sheet 11 and the third sheet 13.

The thickness dimension of the rubber sheet is preferably 2 mm or more and 4 mm or less for the following reasons. If the thickness of the rubber sheet is less than 2 mm, the degree of adhesion between the first sheet 11 and the third sheet 13 may vary, and the tightening force of the clamp 14 may not be reliably transmitted to the first sheet 11. Further, when the thickness dimension of the rubber sheet exceeds 4 mm, the tightening force of the clamp 14 may be absorbed by the rubber sheet and may not be efficiently transmitted to the first sheet 11.

Examples of the rubber sheet include butyl rubber, natural rubber (NR), nitrile rubber (NBR), chloroprene / neoprene rubber (CR), silicone rubber (Si / SR / VMQ / Q), and fluororubber / byton (FKM / FPM). , Afras / Fluorine rubber (FKM), Butyl rubber (IIR), Ethylenepropylene rubber (EP / EPT / EPDM), Chlorosulfonated polyethylene rubber / Hyparon (CSM), Urethane rubber (PUR / U), etc. Can be done.

(Third sheet)
The third sheet 13 is arranged outside the second sheet 12. The third sheet 13 is attached so as to be in close contact with the second sheet 12. Further, the third sheet 13 is bent in a curved shape in the same manner as the first sheet 11 and the second sheet 12.

The third sheet 13 is composed of a sheet having a higher rigidity than the second sheet 12. The third sheet 13 is preferably made of a metal sheet (for example, stainless steel, carbon steel, titanium, etc.). Metal sheets are less likely to be deformed than rubber sheets. Therefore, when the second sheet 12 is sandwiched between the first sheet 11 and the third sheet 13 and pressed by the clamp 14, the tightening force of the clamp 14 is transmitted to the second sheet 12 with almost no attenuation. Can be done. Further, since the second sheet 12 and the third sheet 13 are in contact with each other on the surface, the tightening force of the clamp 14 can be transmitted from the third sheet 13 to the second sheet 12 as a surface pressure (contact pressure per unit area). ..

(Clamp)
The clamp 14 presses the first sheet 11 against the water leak portion 2 of the sealing water pipe 1 via the second sheet 12 and the third sheet 13. The clamp 14 is screwed into a U-shaped bolt 15 having male screws 15a formed on both ends, a washer 16 having a through hole 16a through which the male screw 15a portion of the bolt 15 can be inserted, and a male screw 15a of the bolt 15. It has a possible nut 17. The term "insertion" described here means that the screws are inserted through, and the term "screw" means that the screws are engaged with each other by rotation.

The bolt 15 is arranged so as to sandwich the first sheet 11, the second sheet 12, and the third sheet 13 between the seal water pipe 1 and the bolt 15. The male screws 15a at both ends of the bolt 15 are inserted into the through holes 16a of the washer 16 corresponding to each. The washer 16 is made of a flat metal plate. The washer 16 is arranged on the outer peripheral direction of the seal water pipe 1 on the side opposite to the first sheet 11 and the water leak portion 2. The nut 17 is composed of a hexagon nut or the like. The nut 17 is screwed into the male screw 15a through which the through hole 16a of the washer 16 is inserted.

<3. How to stop the sealing water piping ＞
Next, a water stopping method for the sealing water pipe according to the embodiment of the present invention will be described.
First, if a pinhole or the like is generated in the seal water pipe 1 and the seal water is leaking from the pinhole, the first sheet 11 is attached so as to close the water leak portion 2, and then the second sheet 12 is attached from above. Stack and install. At that time, if the sealing water is vigorously ejected from the water leaking point 2, the first sheet 11 is brought into contact (adhesion) with the outer peripheral surface of the sealing water pipe 1 at a position slightly offset from the water leaking point 2. In that state, the first sheet 11 may be displaced in the length direction of the sealing water pipe 1 to close the water leakage portion 2.

Next, after the third sheet 13 is superposed on the outside of the second sheet 12, the three sheets (11, 12, 13) are sandwiched together with the sealing water pipe 1 by the clamp 14. At that time, the U-shaped bent portion of the bolt 15 is brought into contact with the outside of the third sheet 13. Further, the male screws 15a formed at both ends of the bolt 15 are inserted into the through holes 16a of the washer 16 corresponding to each. Then, the nut 17 is screwed into the male screw 15a protruding from the washer 16 and tightened.

As a result, the sealing water pipe 1 and the three sheets (11, 12, 13) are sandwiched by the clamp 14. Further, the tightening force of the nut 17 is transmitted to 111 via the third sheet 13 in contact with the U-shaped portion of the bolt 15 and the second sheet 12 inside the third sheet 13. As a result, the first sheet 11 is pressed against the water leak portion 2 of the seal water pipe 1. This makes it possible to stop the leakage of the sealing water.

<4. Effect of embodiment>
According to the embodiment of the present invention, the first sheet 11 is arranged so as to cover the water leakage portion 2 of the sealing water pipe 1, and the second sheet 12 and the third sheet 13 are arranged from the outside by the force of the clamp 14. The first sheet 11 is pressed against the water leaking portion 2 of the sealing water pipe 1 to stop the water. As a result, it is possible to repair the water leakage of the seal water pipe 1 without stopping the operation of the device using the mechanical seal on the shaft seal portion. Further, since the water leaking portion 2 is directly closed by the first sheet 11 having a higher pressure resistance than the second sheet 12, the water leaking portion 2 is directly closed by the second sheet 12 having a higher elasticity than the case where the water leaking portion 2 is directly closed. It becomes difficult to make holes in the sheet. Further, since the second sheet 12 having high elasticity is arranged between the first sheet 11 and the third sheet 13, the third sheet 13 having higher rigidity is arranged outside the second sheet 12. , The force of the clamp 14 can be efficiently transmitted to the first sheet 11. As a result, the recurrence of water leakage after repair can be effectively suppressed.

<Examples and Comparative Examples>
(Example)
The pinholes generated in the sealing water pipe were covered with a fluororesin sheet, and a rubber sheet and a metal sheet were arranged in order on the outside of the fluororesin sheet. Then, these three sheets were clamped together with the sealing water pipe. The diameter (nominal diameter) of the sealing water pipe was 1/2 inch, the pressure of the sealing water was 7,000 KPaG, the thickness dimension of the fluororesin sheet was 3 mm, the thickness dimension of the rubber sheet was 3 mm, and the thickness dimension of the metal sheet was 4 mm. A U-shaped bolt, a washer, and two nuts were used for the clamp, and the fluororesin sheet was pressed against the sealing water pipe by tightening the nuts. As a result, the water leak in the seal water pipe stopped, and the water leak did not recur even two months after the repair.

(Comparison example)
A rubber sheet was used to cover the pinholes generated in the sealing water pipe, and a metal sheet was placed on the outside of the rubber sheet. Then, these two sheets were clamped together with the sealing water pipe. The diameter (nominal diameter) of the sealing water pipe was 1/2 inch, the pressure of the sealing water was 7,000 KPaG, the thickness of the rubber sheet was 3 mm, and the thickness of the metal sheet was 4 mm. A U-shaped bolt, a washer, and two nuts were used for the clamp, and the rubber sheet was pressed against the sealing water pipe by tightening the nuts. As a result, although the water leakage from the sealing water pipe was temporarily stopped, the rubber sheet had a hole and the water leakage recurred about 20 minutes after the repair.

<5. Deformation example, etc.>
The technical scope of the present invention is not limited to the above-described embodiment, but also includes a form in which various changes and improvements are made to the extent that a specific effect obtained by the constituent requirements of the invention and the combination thereof can be derived.

For example, in the above embodiment, the case of repairing a water leak due to a pinhole generated in the seal water pipe 1 has been described, but the present invention is not limited to this, for example, a crack generated in the seal water pipe 1 and the like. It can also be applied to repair water leaks caused by other factors.

Further, in the above embodiment, the clamp 14 is configured by using the bolt 15, the washer 16, and the two nuts 17, but for example, for the purpose of preventing loosening, a flat washer or a spring washer is used between the washer 16 and the nut 17. A double nut structure in which two nuts 17 are stacked may be adopted. Further, in order to suppress the deformation of the washer 16 due to the tightening of the nut 17, a plurality of plate-shaped washers 16 may be stacked and used. Further, the clamp 14 may have any structure as long as the first sheet 11 can be pressed against the sealing water pipe 1 as described above.

1 ... Seal water piping 2 ... Water leak point 11 ... 1st sheet 12 ... 2nd sheet 13 ... 3rd sheet 14 ... Clamp 15 ... Bolt 16 ... Washer 17 ... Nut

Claims (8)

It is a water-stop structure for the seal water pipe that stops water leaks that occur in the seal water pipe for supplying seal water to the mechanical seal.
A first sheet arranged so as to cover the leaked portion of the sealing water pipe having an internal pressure of 1000 KPaG or more and 7000 KPaG or less.
A second sheet arranged outside the first sheet and
A third sheet arranged outside the second sheet and
A clamp for pressing the first sheet against the leaked portion of the sealing water pipe via the second sheet and the third sheet is provided.
The first sheet has a higher pressure resistance than the second sheet, has a pressure resistance to the seal water flowing through the seal water pipe, and is configured to be bendable along the outer peripheral surface of the seal water pipe.
The second sheet has higher elasticity than the first sheet.
The third sheet has a water-stop structure for a sealing water pipe having a higher rigidity than the second sheet. The water-stopping structure for a sealing water pipe according to claim 1, wherein the first sheet is made of a fluororesin sheet. The water-stopping structure for the sealing water pipe according to claim 1 or 2, wherein the second sheet is made of a rubber sheet. The water-stopping structure for a sealing water pipe according to any one of claims 1 to 3, wherein the third sheet is made of a metal sheet. The clamp has a U-shaped bolt having male screws formed on both ends, a washer having a through hole through which the male screw portion can be inserted, and a nut that can be screwed into the male screw.
The item according to any one of claims 1 to 4, wherein the sealing water pipe, the first sheet, the second sheet and the third sheet are sandwiched between the bolt and the washer, and the nut is tightened. The water-stop structure of the sealed water piping described. The water-stop structure for a sealing water pipe according to claim 2, wherein the fluororesin sheet has a thickness dimension of 2 mm or more and 4 mm or less. The water-stop structure for a sealing water pipe according to claim 3, wherein the thickness of the rubber sheet is 2 mm or more and 4 mm or less. The water-stop structure for a seal water pipe according to any one of claims 1 to 7, wherein the seal water pipe has a nominal diameter of 3/8 inch or more and 1 inch or less.

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