Method for manufacturing a valve spindle

Patent metadata

Field	Value
Publication number	US-9616498-B2
Application number	US-201414778096-A
Country	US
Kind code	B2
Filing date	Mar 11, 2014
Priority date	Mar 18, 2013
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

A method for manufacturing a valve spindle having a valve disc and a valve stem, the method comprising the steps of: providing a capsule, which defines at least a portion of the valve disc; arranging, in the capsule, a preformed core body that includes a core head, which constitutes an inner portion of the valve disc; arranging a preformed annular valve seat in the capsule, wherein the valve seat is arranged such that the inner circumferential side of the valve seat at least partially defines an inner space around the core head; filling the inner space with a first metallic material, forming the buffer layer, such that the core head is covered with the first material; filling the capsule with a second metallic material, forming the cladding layer; subjecting the capsule to Hot Isostatic Pressing (HIP) at a predetermined temperature, a predetermined isostatic pressure and for a predetermined time so that the preformed core body, the buffer layer, the cladding layer and the valve seat are bonded metallurgically.

First claim

The invention claimed is:

1. A method for manufacturing a valve spindle having a valve disc and a valve stem, the method comprising the steps of:
providing a capsule which defines at least a portion of the valve disc;
arranging, in said capsule, a preformed core body that includes a core head, which constitutes an inner portion of the valve disc;
arranging a preformed annular valve seat in said capsule, wherein the valve seat is arranged such that the inner circumferential side of the valve seat at least partially defines an inner space around the core head;
filling the inner space with a first metallic material, which will form a buffer layer, such that the core head is covered with said first material;
filling the capsule with a second metallic material, which will form a cladding layer; and
subjecting said capsule to Hot Isostatic Pressing at a predetermined temperature, a predetermined isostatic pressure and for a predetermined time so that the preformed core body, the buffer layer, the cladding layer and the valve seat are bonded metallurgically.

2. The method according to claim 1 , wherein the diameter of the annular valve seat is selected such that a predetermined spacing is achieved between the inner circumferential side of the valve seat and the core head.

3. The method according to claim 2 , wherein the valve seat extends a predetermined distance above an upper surface of the core head.

4. The method according to claim 1 , wherein a seat side of the capsule defines a bottom of the space.

5. The method according to claim 1 , wherein the capsule includes an upper capsule portion, which defines the shape of the valve disc of the valve spindle and wherein the core head includes an upper surface and an edge portion, the core head extending into the upper capsule portion and thereby forming an internal portion of the valve disc.

6. The method according to claim 5 , wherein the upper capsule portion includes the lower seat side, and wherein the preformed core body includes a seat portion, wherein the preformed core body is arranged in the capsule such that the seat portion of the preformed core is in contact with the lower seat side of the capsule and such that the head core extends into the space defined by the upper capsule portion.

7. The method according to claim 6 , wherein the valve seat has a lower seat side, the valve seat being arranged in the capsule such that the lower side of the valve seat is in contact with the lower seat side of the upper capsule portion and wherein the valve seat extends into the space defined by the upper capsule portion such that inner circumferential wall extends beyond the upper surface of the core head.

8. The method according to claim 1 , wherein the valve seat is manufactured from sintered particulate metallic material.

9. The method according to claim 1 , wherein an outer space is formed between the upper capsule portion of the capsule and the annular valve seat and the buffer layer, whereby the outer space is filled with the second metallic material forming the cladding layer.

10. The method according claim 1 , wherein the preformed core body includes a head portion which constitutes an inner portion of the valve disc and a valve stem.

11. The method according to claim 1 , wherein the preformed core body includes the head portion and wherein a valve stem is attached to the core body after Hot Isostatic Pressing.

12. A valve spindle including a valve disc having an exhaust side and a valve stem, wherein said valve disc comprises:
a preformed core body, a buffer layer, an outer cladding layer and a preformed annular valve seat;
said preformed core body including a core head which forms an inner portion of the valve disc, wherein the core head includes a top surface directed towards an exhaust side of the valve spindle and an edge surface, the buffer layer being arranged such that it covers the core head, wherein the preformed annular valve seat is arranged between the buffer layer and the cladding layer and surrounds the core head and in that the preformed annular valve seat, in direction towards the exhaust side of the valve disc, extends along the buffer layer of the core head.

13. The valve spindle according to claim 12 , wherein the preformed annular valve seat has an inner circumferential wall, wherein the inner circumferential wall extends, in a direction towards the exhaust side of the valve disc, along the buffer layer on the edge portion of the core head.

14. The valve spindle according to claim 13 , wherein the inner circumferential wall extends beyond the top surface of the core head.

15. The valve spindle according to claim 12 , wherein the preformed annular valve seat includes an outer circumferential wall and wherein the outer circumferential wall is in contact with the cladding layer and inner circumferential wall is in contact with the buffer layer.

Assignees

• Sandvik Intellectual Property

Inventors

• Berglund Tomas

Classifications

• F01L3/04

  Coated valve members or valve-seats · CPC title

• B22F3/15

  Hot isostatic pressing · CPC title

• F16K1/12

  with streamlined valve member around which the fluid flows when the valve is opened · CPC title

• F01L3/00

  Lift-valve, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces; Parts or accessories thereof · CPC title

• B22F7/08 Primary

  with one or more parts not made from powder {(B22F7/062 takes precedence)} · CPC title