GB2269649A - Condensate trap - Google Patents

Abstract

A condensate trap comprises an outer housing (1) having an inlet (2), an outlet (4) and an opening (6). An inner housing (12) supports a temperature actuated valve assembly (20, 22) and is rotatably received within the outer housing (1). The valve assembly is responsive to the presence of condensate. The inner housing (12) is rotatable between a first position, in which flow between the inlet (2) and the outlet (4) is controlled by the valve assembly, and a second position, in which the inlet (2) and the outlet (4) are closed by the inner housing (12) and in which the opening provides access to the valve assembly (20, 22). <IMAGE>

Description

CONDENSATE TRAP This invention relates to a condensate trap, and particularly a condensate trap in a fluid line which may easily be removed for replacement or servicing.

Condensate traps are commonly used in steam systems, in which circumstances they are usually referred to as steam traps. Their function is to discharge condensed water from the system without allowing steam to escape. If steam is lost from the system, this represents a waste of energy. Steam traps thus commonly comprise a valve which is responsive to the presence of condensate or steam in the vicinity of the valve, so that the valve opens when condensate is present and closes when steam is present.

If the steam trap malfunctions or otherwise needs servicing or inspection, it needs to be removed from the fluid line. Up to now upstream and downstream isolating valves have been provided to close the fluid line when the steam trap is to be removed.

According to the present invention there is provided a condensate trap comprising an outer housing having an inlet and an outlet, and an inner housing, which accommodates a valve assembly which is responsive to the presence of condensate in the vicinity of the valve assembly, the inner housing being rotatably mounted in the outer housing for movement between a first position, in which flow between the inlet and the outlet is controlled by the valve assembly, and a second position, in which the inlet and the outlet are closed by the inner housing, an opening in the outer housing providing access to the valve assembly when the inner housing is in the closed position.

In a preferred embodiment of the present invention, the inlet and the outlet of the outer housing are aligned on the same axis as each other.

The opening may extend perpendicular to the axis of the inlet and the outlet and furthermore the axis of rotation of the inner housing between the first and second positions may be perpendicular both to the common axis of the inlet and the outlet and to the direction in which the opening extends.

The valve assembly may comprise a valve member and a valve seat which are supported separately from each other on the inner housing. In a preferred embodiment, the inner housing has an internal passage, the valve member being supported at one end of the passage and the valve seat being supported at the other. When the inner housing is in the second position, the opening may provide direct access to one of the components of valve assembly (i.e. the valve member or the valve seat), access to the other component being obtained after the first component has been removed.

For example, the valve member may be located in a bore within the inner housing, and the bore may be large enough to allow the valve seat to pass through it after the valve member has been removed.

For a better understanding of the present invention and to show how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 shows a condensate trap; Figure 2 is a sectional view of the condensate trap of Figure 1; Figure 3 corresponds to Figure 2 but shows the condensate trap is a different operative condition.

The condensate trap shown in Figure 1 is, in use, fitted in a fluid flow line for discharging condensate that has collected in the system, while preventing steam from escaping. The assembly comprises an outer housing 1 having an inlet 2 and an outlet 4. An opening 6 is provided which is covered by a protective cap 8. The condensate trap further has a handle 10 for the manual selection of the operative condition of the condensate trap. As can be seen in Figure 2, there is provided an inner housing 12 between the inlet 2 and the outlet 4 of the outer casing 1. In the embodiment shown in Figure 2, the inner housing 12 comprises a hollow part spherical member. Two bores 14 and 16 are provided in the wall of the inner housing 12.

An insert 18 is fitted within the bore 16 and receives a valve seat 20. A passage 19 extends through the valve seat to communicate with the outlet 4 of the outer housing. A valve element 22 is supported in the bore 14 which in the embodiment shown in Figures 2 and 3 comprises a valve closure member 24 connected to an expansion chamber 26. Clearance 31 is provided between the bore 14 and the valve element 22. The bore 14 has a step 28 against which a screen 32 abuts. The screen 32 is held in position against the step 28 by a clip 34. The screen 32 therefore serves to locate the valve element 22.

Within the outer housing 1, there are provided seats 36 which locate the inner housing 12 and which provide an abutment for spherical surface portions of the inner housing 12. A top seat 38 is provided which is carried by a seat ring 40 and which provides a seal to enable isolation of the opening 6 from the inlet 2 and outlet 4 of the outer casing 1. A cap seal 42 is disposed between the protective cap 8 and the opening 6 of the outer housing 1.

The inlet 2 of the housing 1 has an internal thread 44. The internal diameter of the inlet 2 is sufficient to enable insertion of the complete inner housing 12 during assembly of the condensate trap. An externally threaded insert 46 is screwed into the threaded inlet 2 to complete assembly of the condensate trap. A housing seal 48 is disposed between the insert 46 and the housing 1.

In the operative position shown in Figure 3, the inner housing 12 has been rotated with respect to the outer housing 1 through 90 . The bore 14 of the inner housing 12 now faces the opening 6.

During normal operation of the condensate trap, the condensate trap will be in the operative condition shown in Figure 2. The inner housing 12 is oriented such that the bore 14 of the inner housing 12 communicates with the inlet 2 of the housing 1 and the bore 16 communicates with the outlet 4. The condensate trap is provided at a lower region of a steam system.

Condensate that has collected in the system will flow through pipework (not shown) into the inlet 2. The condensate will then flow through the screen 32 which acts as a filter to prevent undesired foreign matter from reaching the valve mechanism. The condensate then flows through the clearance 31 provided between the valve member 22 and the bore 14 into a central region of the inner housing 12. The temperature of the condensate results in a reduced volume in the expansion chamber 26 and consequently the valve closure member 24 is moved away from the valve seat 20. As a result, the condensate is able to flow through the passage 19 and the outlet 4. Once all of the condensate has been discharged through the outlet 4, steam will once more enter the interior of the inner housing 12, the temperature surrounding the expansion chamber 26 will rise and, as a result, the valve closure member 24 is pressed against the valve seat 20, to prevent the passage of steam via passage 19 to the outlet 4.

In order to remove the valve assembly for inspection or replacement, the handle 10 is rotated through 90C such that the inner housing is in the second position, shown in Figure 3. The bore 14 of the inner housing 12 is then situated opposite the opening 6 and the valve element may be removed by removing the clip 34 which retains the valve element 22 (together with the screen 32) in position. When the inner housing 12 is in the position shown in Figure 3, spherical outer regions of the inner housing 12 abut the seats 36 and the top seat 38 to isolate the inlet 2, the outlet 4 and the opening 6 from one another.

This obviates the need to use upstream and downstream isolating valves when the condensate trap is to be inspected or replaced.

Once the valve element 22 has been removed from the inner housing 12 through the opening 6, access is gained to the valve seat 20. The valve seat 20 is screwed into the insert 18 and has smaller outer dimensions than the valve element 22, and may consequently be removed through the bore 14 following removal of the valve element 22.

It will be appreciated that other known types of valve assembly may be used in place of the expansion chamber valve assembly shown in the drawings.

Claims (9)

1. A condensate trap comprising an outer housing having an inlet and an outlet, and an inner housing, which accommodates a valve assembly which is responsive to the presence of condensate in the vicinity of the valve assembly, the inner housing being rotatably mounted in the outer housing for movement between a first position, in which flow between the inlet and the outlet is controlled by the valve assembly, and a second position, in which the inlet and the outlet are closed by the inner housing, an opening in the outer housing providing access to the valve assembly when the inner housing is in the closed position.

2. A condensate trap as claimed in claim 1, in which the inlet and the outlet of the outer housing are aligned with each other on a common axis.

3. A condensate trap as claimed in claim 2, in which the opening extends perpendicularly to the common axis of the inlet and the outlet.

4. A condensate trap as claimed in claims 2 or 3, in which the axis of rotation of the inner housing between the first position and the second position is perpendicular both to the common axis of the inlet and to the outlet and to the direction in which the opening extends.

5. A condensate trap as claimed in any preceding claim in which the valve assembly comprises a valve member and a valve seat which are supported separately on the inner housing.

6. A condensate trap as claimed in claim 5, in which, when the inner housing is in the second position, removal of one of the valve member and the valve seat provides access to the other.

7. A condensate trap as claimed in claim 6, in which the valve member is mounted in a bore in the inner housing, the bore being sufficiently large to allow the passage of the valve seat through the bore.

8. A condensate trap as claimed in any preceding claim, in which the inner housing has a part-spherical outer surface by which the inner housing is rotatably supported within the outer housing.

9. A condensate trap substantially as described herein, with reference to, and as shown in, the accompanying drawings.