JPS58135376A - Method of fixing outer casing flange of valve water turbine - Google Patents

Abstract

PURPOSE:To enable to shorten the term of installation work, by pouring foundation concrete after coupling a small-diameter end portion of a casing body located on the downstream side of the same and an upstream-side coupling portion of a guide vane ring fixing outer casing flange together temporarily. CONSTITUTION:An outer casing 10 is connected to stay vanes buried in a concrete foundation 15 before attaching a flange 11 to the casing 10, and its position relative to an inner casing 13 is determined. Then, a jig 21 in the form of a bottomed cylinder is coupled to the casing in the manner that the flange 11 of the outer casing 10 is held in engagement with a flange surface 21b of the jig 21 and the downstream-side end face 13a of the inner casing 13 is held in engagement with the bottom 21a of the jig 21. In this state, anchor bolts 14 are welded to the upstream-side surface of the flange 11, and then foundation concrete is poured around the main body 10a of the outer casing 10. After hardening of the concrete, the main body 10a and the flange 11 are welded together at their coupling portion 22, and then the jig 21 is removed. By employing such a method, it is enabled to form a flange surface requiring correct horizontality and verticality and to shorten the term of installation work by eliminating the correction machining for the flange surface.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for installing an outer casing 7 flange of a valve water turbine.

This flange is required to have accurate perpendicularity, flatness, and relative position with the downstream end surface of the inner casing because a guide bend ring is attached to the downstream end surface.

FIG. 1 shows a conventional embodiment and is a sectional view of a main part on the downstream side of an outer casing. The outer casing 1° is an outer casing body 1 formed into a funnel shape using a relatively thick steel plate.
An annular outer casing flange 11 on the small diameter end face of 0a
is welded. 7 The downstream end face of the flange 11 is machined to attach a guide ring 121, and the outer casing 1o and the inner casing 13 are connected by a stave ring that is not mixed. Anchor bolts 14 are provided on the upstream side surface of the flange 11, and foundation concrete 15 is poured around the outer casing 10. The water conduit is formed by the outer casing 1°, and the water is
・Flows in the direction of arrow 6.

In such a configuration, the outer casing 1o.

It is connected to stevens (not shown) provided vertically from the upper and lower parts of the inner casing 13, and is surrounded by a foundation concrete! j - Because the guide bend ring I2 mounting surface of the flange 11 is undulated or tilted due to the installation of the guide plate 15, the perpendicularity may be affected.

It had the disadvantage that it required a lot of time to correct it using a grinder to achieve flatness.

The present invention eliminates the above-mentioned drawbacks, and enables the pouring of surrounding foundation concrete by separating the seven lunges from the outer casing, fixing them with a jig, and arranging them so as to be connected to the downstream side of the outer casing. The purpose of this is to obtain an outer casing flange that can ensure the perpendicularity and flatness of the upstream side (1111 plane) of the outer casing body and the flange after hardening by welding. ．． Ta.

FIG. 2 is a sectional view of a main part showing an embodiment of the present invention and showing a method of connecting an outer casing main body with a flange. In (2), components having the same first factor are given the same reference numeral 1] and their explanation will be omitted. Outside (fill casing 10 is the casing body where the flange 11 is not joined) O
In state a, the inner casing 1 is connected to a steven (not shown) that is embedded in the foundation concrete 15 through the peripheral surface, and the inner casing 13 is connected via the steven.
The relative position with 3 has been secured. The flange 11 is an annular flat plate that is individually machined and has an inner circumferential surface that is compatible with the downstream 1ull of the outer casing body Oa. Reference numeral 21 is a cylindrical bottomed jig having an opening 210''f at the bottom 21a and a flange 21bf, which is made for attaching the 7 flange 11 to the outer casing body]OaK.

The jig 21 attaches the flange 1] of the outer casing 1o to the flange surface 21bK, and attaches the bottom part 2]a to the inner casing 1.
By attaching the flange 11 to the downstream end surface 13a of the flange 11, the upstream inner diameter side surface of the flange 11 is attached to the outer casing body 1.
The inner circumferential surface of the flange 11 is in contact with the end surface of the downstream l1111 of Oa, and is configured to be continuous with the inner circumferential surface on the downstream side of the outer casing body 10a. In this state, anchor bolts 14 are welded onto the upstream side surface of flange 11, and foundation concrete 15e is poured around outer casing body 10a. The joint 22 between the outer casing main body 10a and the flange 1 is welded to the extent that it seals the water that seeps in from the inside of the foundation concrete IJ-5 after the foundation concrete 15 has hardened, and the jig 21 is removed.

In the upper dC the outer casing 100 norange 1] is
The foundation concrete I7-15 is poured and hardened.

The flange 11 is fixed by a jig 21 until it is welded to the joint 22 with the outer casing main body 10a, and the hydraulic thrust acting on the flange 11 via a guide bend ring (not shown) is transmitted to the foundation concrete seam 5 by the anchor bolt 4. Since the outer casing 10 is not subjected to direct force, welding can be done at the level of a seal that does not require any strength, and a 7-lunge surface that undergoes extremely little deformation during assembly, installation, and concrete pouring of the outer casing 10 can be obtained.

As described above, the present invention can form a flange surface that requires accurate perpendicularity and flatness on the outer casing.
It is possible to provide a method for attaching an outer casing flange 5- of a valve water turbine, which can largely omit correction work on the flange surface, shorten the installation period, and reduce installation costs.

4. Brief description of the drawings Figure 1 shows a conventional embodiment and is a cross-sectional view of the main part on the downstream side of the outer casing, and Figure 2 shows the embodiment of the present invention and shows the main part of the connection method between the outer casing and the 7 flange. FIG.

]0...Outer casing, 10a...Outer casing body, 11...Outer casing flange, 12...
・Guide bend ring, 13a...Inner casing downstream end face, 15...Foundation concrete, 2]...Cure A
, 2]a...bottom of the jig, 211)...7 langes of the jig, 21c...opening of the jig, 22...junction.

6- 1 figure Figure 2 E3Q:,! 'Ic

Claims (1)

[Claims] 1) In a funnel-shaped outer casing of a valve water turbine, which is composed of an outer casing body and an annular guide bend ring mounting outer casing flange, the downstream small-diameter end face of the casing body and the inner diameter side face on the upstream side of the flange are mutually connected. After temporarily joining the separated joints with a jig, foundation concrete is cast around the outer casing, and after the foundation concrete has hardened, the jig is removed and the inner peripheral wall of the joint is welded. Method for adding 7 langes to the outer casing of a valve water turbine, characterized in that they are joined together, 2.
The method for attaching an outer casing flange according to claim 1, wherein the jig has an opening at the bottom and is a flanged bottomed cylindrical type. Method.