JPS6316472B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a corrosion-resistant flange, and more particularly to a corrosion-resistant flange for preventing electrolytic corrosion that occurs when seawater is transferred by a rotary pump or the like.

When transporting seawater using a rotary pump that contains dissimilar metal objects, such as cast iron and gunmetal,
It is known that metals are eroded by electrolytic corrosion. In order to prevent this, conventional methods have been used to protect the pump body by arranging a zinc body, which is likely to corrode the fastest, in close proximity to the area where electrolytic corrosion is expected to occur, and eluting this body first. .

In particular, when pumping seawater with a rotary pump, the function of the pump is often lost due to electrolytic corrosion, and as a countermeasure, a method is used, for example, to fix a rod-shaped or block-shaped zinc body protruding from the water passage. .

However, this conventional method had the following drawbacks.

(b) It is difficult to install a zinc body of sufficient size due to the size of the water passage.

(b) If a zinc body with a large volume protrudes into the water passage, it will obstruct the flow of water and reduce the function of the pump.

(c) Special holes, screws, etc. must be provided on the pump to attach the zinc body.

(d) Since the elution of zinc bodies cannot be inspected from the outside,
If elution progresses excessively, the zinc body will be lost and the function of the pump will be impaired.

SUMMARY OF THE INVENTION An object of the present invention is to provide a corrosion-resistant flange which overcomes the above-mentioned drawbacks and has a simple structure, is easy to install, and allows inspection of the elution status from the outside.

To this end, according to the present invention, the outer periphery and both side surfaces of the annular zinc body are covered with a rigid body, and the inner circumferential surface of the zinc body is configured to be exposed.

Furthermore, in practice, a screw plug can be removably attached from the outer peripheral surface of the covering rigid body toward the zinc body.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

In FIGS. 1 and 2, reference numeral 1 denotes an annular zinc body, the outer periphery and both sides of which are covered with a rigid body 2 having sufficient strength such as a cast iron flange. The inner circumferential surface of the tube is open, and the inner circumferential surface is exposed to the water flow. Sheet packing 3 is attached to both sides of the rigid body 2 covering the annular zinc body 1. Further, a screw plug 4 having a leak-proof gasket 5 is removably screwed from the outer periphery of the rigid body 2 toward the zinc body. The plug 4
A deep hole 6 is bored on the side of the zinc body 1 at the tip thereof, leaving a certain thickness of the zinc body so as not to penetrate into the water flow.

When the corrosion-resistant flange having the above structure is used in a rotary pump, it is sandwiched between the pump-side flange 8 and the piping-side flange 9, and is firmly fastened with a plurality of bolts 10 to prevent water or air leakage. In the figure, 11 indicates a pump, and 12 indicates a motor.

A corrosion-resistant flange like this is attached to the pump suction port,
If they are clamped at the discharge port or the flanges of the inlet and outlet of the valve, the zinc material will be eluted first when electrolytic corrosion occurs, thus preventing the pump body from being eroded. Also, after installation, try loosening the screw plug 4 on the outer periphery once every few months. At this time, if water does not come out, it means that the effective volume of the zinc body still remains, and if water leaks out, it means that the zinc body has progressed to elute and the deep hole 6 has penetrated into the water flow. This indicates that the flange needs to be replaced, so replace it with a new one.

If electrolytic corrosion progresses quickly, the effective amount of zinc will be increased and the effect will be enhanced by stacking and sandwiching two or three corrosion-resistant flanges of the present invention.

That is, according to the corrosion-resistant flange according to the present invention, a required amount of zinc body can be installed without obstructing the water passage, so that the effect of preventing galvanic corrosion is high.

In addition, in the corrosion-resistant flange of the present invention, not only the outer periphery of the annular zinc body but also both sides are coated with a rigid body, so that the zinc is almost uniformly eluted from the inner circumferential surface, and the corrosion-proofing effect is maintained for a long period of time. It has the characteristics of being able to Since it can be easily attached to the pump body without any processing, it can also be used with conventional pumps. Furthermore, the degree of elution of the corrosion-resistant flange can be checked by simply loosening the screw plug 4 without having to pull out the zinc body or stop the pump. It is also easy to increase the amount.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the corrosion-resistant flange of the present invention, Fig.
The figure is an external view showing how the corrosion-resistant flange is used. 1... Annular zinc body, 2... Rigid body, 3... Sheet packing, 4... Plug, 5... Leakproof packing, 6... Deep hole.

Claims (1)

[Claims] 1. In a corrosion-resistant flange for preventing electrolytic corrosion caused by seawater, etc., the outer periphery and both sides of an annular zinc body are covered with a rigid body, and the inner circumferential surface of the zinc body is exposed. A corrosion-resistant flange characterized by being configured as follows. 2. The corrosion-resistant flange according to claim 1, characterized in that a screw plug is removably attached from the outer peripheral surface of the coated rigid body toward the zinc body.