JPH0819435B2 - Anti-seizure agent for threads - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an agent for preventing seizure of a threaded portion, and more particularly, to prevent seizure of the threaded portion of a valve rod of a valve or a bolt for fastening a flange for a long period of time. It relates to an anti-seizure agent.

[0002]

BACKGROUND OF THE INVENTION A large number of bolts for fastening flanges of piping valves, piping, equipment and the like are installed in various plants such as petroleum refining, petrochemical and the like.

The threaded portion of the valve rod of a piping valve and the threaded portion of a bolt for flange tightening of piping, equipment, etc. cause seizure when the fluid in the piping is at a high temperature. Since the operation of the piping valve is performed via the threaded portion engraved on the valve stem, if the threaded portion of the valve stem is seized, the valve operation becomes difficult. Further, if the threaded portion of the flange tightening bolt of piping, equipment, etc. is seized, the flange cannot be removed unless the threaded portion is burnt out during repair work, etc., and repair work cannot be carried out smoothly.

Therefore, conventionally, a seizure-preventing lubricant prepared by mixing a metal powder such as copper or molybdenum disulfide or a metal oxide powder with a lubricating oil such as mineral oil is applied to the screw portion,
A method of preventing seizure was adopted.

However, in the conventional anti-seizure lubricant, a sufficient amount of the lubricant is unlikely to penetrate into the threaded portion. Therefore, if the fluid in the pipe is at a high temperature, the threaded portion will seize in a short period of time. , There was a problem of sticking.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks of conventional anti-seizure lubricants, and does not cause seizure for a long period of time even when used under various high temperature conditions. It is an object of the present invention to provide an anti-seizure agent.

[0007]

Means for Solving the Problems The inventors of the present invention, when a seizure preventing lubricant is mixed with a penetrant, the seizure preventing lubricant permeates into the thread portion of a valve rod of a valve or a tightening bolt of a flange. However, we paid attention to the fact that the fitting gap of the screw is filled and the lubrication effect is fully exerted. And, by changing the mixing ratio of the anti-seizure lubricant and the penetrant according to the operating temperature condition,
As a result of repeated studies and experiments, the present invention has been completed.

That is, the seizure preventive agent of the screw portion according to the present invention is a seizure preventive lubricant 20 to 5 containing metal powder and / or metal oxide powder and mineral oil and / or synthetic oil as essential components.
0 to 50% by weight of a penetrant and 50% to 80% by weight of the penetrant, wherein the penetrant is a light oil fraction composed of an aromatic solvent and a normal paraffin-based petroleum solvent.
Neutral normal paraffinic heavy oil fraction 20-
50% by weight, and the light oil fraction is characterized by comprising 20 to 50% by weight of an aromatic solvent and 50 to 80% by weight of a normal paraffinic petroleum solvent.

In a preferred embodiment of the present invention, the metal powder and / or metal oxide powder of the anti-seizure lubricant is mainly composed of Cu or Mo having a particle size of 100 μm or less, and a mineral oil and / or a synthetic oil is used. That is, the boiling point is 300 ° C. or higher. Hereinafter, the present invention will be described in detail.

The anti-seizure lubricant used in the present invention contains Al, Cu, Fe, Mo, Zn, other various metal powders and / or metal oxide powders, and mineral oil and / or synthetic oil as essential components. .

The metal powder and / or the metal oxide powder has a particle size of 1 because of the affinity with the screw portion and the uniform dispersibility in the screw portion.
It is preferable that the main component is Cu or Mo having a thickness of 00 μm or less.

The mineral oil and the synthetic oil may be used alone or as a mixture, but in order to use them in a high temperature part, the boiling point is 3
It is preferably at least 00 ° C.

The mixing ratio of the metal powder and / or the metal oxide powder and the mineral oil and / or the synthetic oil can be appropriately selected according to the operating temperature conditions of the present invention.

The metal powder and / or the metal oxide powder has a lubricating effect on the threaded portion. Further, the mineral oil and / or the synthetic oil has an action of reducing frictional resistance of the screw portion and facilitating attachment / detachment.

When the amount of the metal powder and / or the metal oxide powder is small, the lubricating effect is not sufficient. Further, when the amount of mineral oil and / or synthetic oil is small, the frictional resistance of the threaded portion increases. For this reason,
The mixing ratio of the metal powder and / or the metal oxide powder and the mineral oil and / or the synthetic oil is preferably 0.8 to 1.2: 1.2 to 0.8, and most preferably 1: 1.

As the penetrant, a penetrant having a light oil fraction composed of an aromatic solvent such as xylene and a normal paraffinic petroleum solvent and a normal paraffinic heavy oil fraction as components is preferable.

The above light oil fraction comprises about 20 to 50% by weight of an aromatic solvent such as xylene and about 5 parts of a paraffinic petroleum solvent.
It is preferably from 0 to 80% by weight. The heavy oil fraction is preferably 60-80 neutral oil obtained by solvent refining or hydrogenation refining. Further, the blending ratio of the light oil fraction and the heavy oil fraction is preferably about 50 to 80% by weight of the light oil fraction and about 20 to 50% by weight of the heavy oil fraction.

The mixing ratio of the seizure preventing lubricant and the penetrant is 20 to 50% by weight of the seizure preventing lubricant and the penetrating agent 5.
It is 0 to 80% by weight. The blending ratio is appropriately selected depending on the operating temperature condition of the threaded portion. As the operating temperature increases, the mineral oil and / or synthetic oil component of the seizure prevention lubricant evaporates and evaporates. Therefore, increase the proportion of seizure prevention lubricant and decrease the penetrant. There is a need. Table 1 below shows a preferable blending ratio for each operating temperature condition.

[0019]

[Table 1]

If the blending ratio of the anti-seizure lubricant is less than 20% by weight, the anti-seizure effect is not sufficient. Further, if the blending ratio of the penetrant is less than 50% by weight, the seizure preventing lubricant does not sufficiently penetrate into the threaded portion, and the seizure preventing effect of the seizure preventing lubricant cannot be sufficiently exhibited.

The anti-seizure agent of the screw portion of the present invention includes rust preventives (alkali metal and alkaline earth metal sulfonates, metal soaps, etc.), surfactants (nonionic, cationic, anionic). In addition, it does not matter to add the additives usually added to the anti-seizure lubricant.

When using the anti-seizure agent for the threaded portion of the present invention, it may be formed into a paste with a thickener and applied to the threaded portion by a usual method. By thus forming a paste with a thickener, application and handling to the threaded portion can be facilitated, and the effects of the anti-seizure lubricant and penetrant can be maintained even under harsh environmental conditions.

The thickener is not particularly limited, but metal soap such as calcium soap can be used.

[0024]

EXAMPLES The effects of the present invention will be illustrated below based on examples.

Example 1 An anti-seize composition having the following composition was prepared.

Compounding amount Metal powder (Cu fine particles having a particle size of 100 μm or less) Table 2 Mineral oil (kinematic viscosity at 100 ° C. 8.1 cSt, boiling point 410 ° C.) Table 2 Penetrant (light oil fraction (xylene 40% by weight, Paraffin petroleum solvent 60% by weight) 70% by weight and paraffinic heavy oil fraction (80 neutral oil) 30% by weight)

Next, calcium soap was added as a thickener to the above composition to obtain a paste-like anti-seizure agent for the screw portion.

Then, the above paste-like anti-seizure agent is applied to the fitting gap of the thread portion of the valve rod of the piping valve for oil / steam under various high temperature conditions shown in Table 2,
By properly loosening the tightening parts of bolts and nuts, the seizure status of the threaded parts can be checked by setting the pipe valve temperature to 35
Those below 0 ° C were observed for 3 years, and those above 350 ° C were observed for 1 year and 6 months.

The anti-seizure effect was evaluated according to the following criteria. [Evaluation Criteria] ◯: Good (a smooth loosening operation is possible without causing seizure.) Δ: Fair (although there is some resistance to the loosening operation, it is not a practically problematic level.) × : No (because of seizure, it is difficult to loosen.) The above evaluation results are shown in Table 2.

In addition, the experiment No. 1-31, 3
4, 36, 37, 38, 41 and 43 are copper fine particles and mineral oil (kinematic viscosity at 100 ° C. 8.1 cSt, boiling point 410).
(° C) is a commercially available lubricant for preventing seizure.

[0031]

[Table 2]

[0032]

[Table 3]

As is clear from Table 2, Experiment No. 1 using a commercially available anti-seizure lubricant was used. 1-31, 34, 3
Nos. 6, 37, 38, 41, and 43 all suffered seizure in less than one year, and the threaded portion of the valve stem of the valve was fixed to the valve stem.

On the other hand, in Experiment No. in which the piping valve temperature was less than 350.degree. 1-2-4, 1-6, 1-8-11, 1
-14 to 16 and 1 to 19 to 22 did not cause seizure even after 3 years, and the tightened portions of the bolts and nuts could be loosened easily, and there was no hindrance to the valve operation.
Experiment No. with piping valve temperature of 350 ° C or higher 1-24 ~
25, 1-27 to 28, 1-30 were similar even after 1 year and 6 months. Experiment No. 1-1, 5, 7, 1
Nos. 2, 13, 17, and 18 were after 3 years, and the experiment No. At the time of one year and six months, 1-23, 26, and 29 had some resistance to loosening of the tightening portions of the bolts and nuts, but did not hinder valve operation.

The comparative experiment No. 1-32, 33,
Nos. 35, 39, 40, 42, 44, and 45 have the same composition as that of the example, and the mixing ratio of the anti-seizure lubricant and the penetrant is outside the range of the present invention. It turns out that the object of the invention cannot be achieved.

Example 2 The effect was confirmed in the same manner except that a composition similar to that of Example 1 was prepared and a paste-like anti-seizure agent was applied to the threaded portion of the pipe / heat exchanger flange. The evaluation results are shown in Table 3.

In addition, the experiment No. 2-29, 3
Nos. 2, 34, 35, 38 and 40 use the same commercially available anti-seizure lubricant as described above.

[0038]

[Table 4]

[0039]

[Table 5]

As is apparent from Table 3, Comparative Experiment No. 1 using a commercially available anti-seizure lubricant was used. 2-29, 3
All of 2, 34, 35, 38, and 40 suffered seizure in less than one year, and the screw parts were fixed.

On the other hand, in Experiment No. in which the pipe / heat exchanger flange temperature was less than 350 ° C. 2-2-4, 6, 8-1
Nos. 1, 14 to 16 and 19 to 22 did not seize even after 3 years, and the tightened portions of the bolts and nuts could be loosened easily. Experiment No. with piping / heat exchanger flange temperature of 350 ° C or higher 2-24, 25, 27, 28
Was the same after 1 year and 6 months. Also, experiment N
o. Nos. 2-1, 5, 7, 12, 13, 17, and 18 were measured after 3 years, and the experiment No. Although 2-23 and 26 had some resistance at the end of 1 year and 6 months,
I was able to loosen the bolts and nuts.

Example 3 In the same manner as in Examples 1 and 2, the same experiment was carried out using a mineral oil having a boiling point of 300 ° C. instead of the mineral oil having a boiling point of 410 ° C. in the anti-seizure lubricant. The effect of the invention is obtained.

[0043]

According to the present invention, the seizure-preventing lubricant and the penetrant are mixed in an appropriate amount according to the operating temperature, so that the seizure-preventing lubricant is sufficiently permeated into the fitting gap of the threaded portion to provide lubrication. Since the coating is formed, seizure of the threaded portion can be prevented for a long period of time even when the fluid in the pipe has a high temperature.

As a result, by using the seizure preventive agent for the threaded portion of the present invention, the valve operation of the pipe can be facilitated. Further, it is not necessary to burn out the fixed screw portion at the time of repairing the pipes / equipment, etc., and work safety, efficiency, and fire prevention can be achieved.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C10M 127: 06 159: 04) C10N 10:02 10:12 20:00 A 20:06 Z 30: 06 30:08 50:10

Claims (1)

[Claims] 1. An anti-seizure lubricant comprising metal powder and / or metal oxide powder and mineral oil and / or synthetic oil as essential components.
By mixing 20 to 50 wt% and penetrant 50-80 wt% <br/> Ri Na, the penetrant, aromatic solvents and normal paraffinic
50-80% by weight of light oil fraction consisting of petroleum solvent
0-80 Neutral Normal Paraffin Heavy Oil Distillation
20 to 50% by weight of the mixture, and the light oil
The fraction is 20-50% by weight of aromatic solvent and normal paraffin.
An anti-seizure agent for screw parts, which comprises 50 to 80% by weight of a petroleum-based solvent .