JPH1089595A - Pilot type steam trap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of water hummer by operating pressure responding valve by opening/closing a plurality of pilot valve port in order by deformation of a temperature sensitive member, in a device provided with the pilot valve for operating the pressure responding valve. SOLUTION: The inside of a trap casing is sectioned into a condensation reservoir chamber 5 communicated with an inlet 4 and a pressure responding valve housing chamber 7 communicated with an outlet 6 by a partition wall 3, the inlet 4 is opened to an upper part of the condensation reservoir chamber 5, and is communicated through a screen 8, and a pilot valve 9 is installed on the upper end of the condensation reservoir chamber 5. When low temperature condensation is delivered and the temperature of the inlet 4 side is raised, a plurality of pilot valve ports 22 having a small aperture are closed in order from one end side by a bimetal 26 as a temperature sensitive member whose one end is fixed to an outer periphery of the pilot valve element 24 of the pilot valve 9. Therefore, the orifice 11 is gradually closed, pressure in a pressure chamber 10 is reduced bypassing the orifice 20. At this time, a piston 16 is displaced upward, a valve element 17 is seated on a valve seat 13, and a main valve port 14 is gradually closed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam trap for automatically discharging condensate generated in a steam piping system.
In particular, the present invention relates to a pilot type steam trap in which a pressure responsive valve is operated by an on-off valve of a pilot valve.

[0002]

2. Description of the Related Art A conventional pilot-type steam trap will be described with reference to Japanese Utility Model Publication No. 48-100430.
This includes a pressure chamber partially formed by the pressure receiving displacement wall of the pressure responsive valve, a first orifice communicating the pressure chamber to the inlet side,
A second orifice connecting the pressure chamber to the outlet side, and a pilot valve port at the inlet side end of the first orifice are opened and closed according to the temperature on the inlet side, and condensate is introduced into the pressure chamber to control the pressure in the pressure chamber. Thus, a pilot valve for operating a pressure responsive valve is provided, and the pilot valve is formed of a bimetallic temperature sensing member and a pilot valve port having a single opening.

[0003]

In the conventional pilot type steam trap described above, the temperature-sensitive member made of bimetal opens or closes by overcoming the fluid pressure acting on the pilot valve port having a single opening. Since it must be maintained, a temperature-sensitive member having a large deformation force is required. Therefore, it is necessary to use a large temperature-sensitive member or combine a plurality of temperature-sensitive members. Further, since the pressure in the pressure chamber rises or falls at a stretch by opening and closing a single pilot valve port, the pressure responsive valve opens and closes rapidly, causing a rapid flow of fluid to the inlet side or the outlet side, resulting in a low pressure. -There was a danger of hammering.

Accordingly, a technical object of the present invention is to provide a pilot type steam trap in which the first orifice can be gradually opened and closed by a small deformation force of a temperature sensing member as a pilot valve and the pressure responsive valve does not open and close rapidly. It is to provide.

[0005]

Means for Solving the Problems The technical means of the present invention taken to solve the above-mentioned technical problems is to provide a pressure chamber partially formed by a pressure receiving displacement wall of a pressure responsive valve, and a pressure chamber. A first orifice communicating with the inlet side, a second orifice communicating the pressure chamber with the outlet side, and a pilot valve port at the inlet end of the first orifice is opened and closed according to the temperature on the inlet side to condense water into the pressure chamber. In those equipped with a pilot valve that operates the pressure responsive valve by introducing and controlling the pressure of the pressure chamber,
A pilot valve is formed by a temperature-sensitive member in which a strip-shaped flat plate is curved and one end thereof is fixed, and a plurality of small-diameter pilot valve ports formed from one end to the other end facing the temperature-sensitive member. A pilot-type steam trap is characterized in that a pressure-responsive valve is operated by sequentially opening and closing a plurality of small-diameter pilot valve ports by deformation of a heating member.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The temperature-sensitive member of the present invention is formed by bending a strip-shaped flat plate and fixing one end thereof.
The degree of curvature changes in accordance with the temperature on the inlet side, and the other end side is greatly displaced and widens or narrows. This allows
A plurality of pilot valves having a small diameter are sequentially opened from the other end of the temperature sensing member, and sequentially closed from one end of the temperature sensing member. As described above, since the present invention opens and closes a plurality of pilot valves having a small diameter sequentially, the temperature sensing member can perform the opening and closing operation with a small deformation force. Further, since the plurality of pilot ports of small diameter are sequentially opened and closed, the first orifice can be gradually opened and closed, and the pressure in the pressure chamber gradually rises or falls. Therefore, the pressure responsive valve can be opened and closed gently, preventing water hammer.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a pilot type steam trap according to a specific embodiment of the present invention, FIG. 2 is an enlarged sectional view of a pilot valve portion of FIG. 1, and FIG.
It is -A sectional drawing.

A lid 2 is fixed to the main body 1 to form a trap casing. Interior of trap casing is partition wall 3
Thereby, a condensate sump chamber 5 communicating with the inlet 4 and a pressure-responsive valve accommodating chamber 7 communicating with the outlet 6 are separated. The inlet 4 opens at the upper part of the condensing chamber 5 and communicates through a screen 8. The outlet 6 is formed on the same axis as the inlet 4. A pilot valve 9 is attached to the upper end of the condensing chamber 5.

A cylinder 12 and a valve seat 13 are arranged in the pressure-responsive valve accommodating chamber 7. The condensate sump 5 and the outlet 6 have a valve seat 13
The main valve port 14 and the fluid passage window 15 open to communicate with each other. A pressure-responsive valve is formed by a piston 16 that slides in the cylinder 12 in an airtight manner, and a valve body 17 that opens and closes the main valve port 14 from the condensate sump chamber 5 side. The valve body 17 has a valve rod 18 penetrating the top wall of the valve seat 13, further penetrating the piston 16, and fixed to the piston 16 by a nut 19. The space above the piston 16 forms the pressure chamber 10 and communicates with the condensate sump chamber 5 via the first orifice 11. The pressure chamber 10 communicates with the outlet 6 through a communication passage 21 opened in the valve seat 13 by a second orifice 20 penetrating the piston 16.

The pilot valve 9 includes a pilot valve body 24 having a plurality of small-diameter pilot valve ports 22 and a communication passage 23 through which the pilot valve port 22 communicates with the first orifice 11. Is formed from a bimetal 26 as a temperature-sensitive member, one end of which is fixed with a screw 25 on the outer periphery. The upper end of the pilot valve element 24 is screwed to the lid 2. Four pilot valve ports 22 are opened in the horizontal direction, and a desired discharge flow rate can be obtained as a whole.
The bimetal 26 is formed by bonding two metals or alloys having different coefficients of thermal expansion together to form a strip, and bending the strip into a low expansion material on the inside and a high expansion material on the outside. When the temperature on the side is low, it expands and when it is high, it narrows. Then, the small-diameter pilot valve ports 22 formed from one end to the other end facing each other are sequentially opened and closed.

When the temperature at the inlet 4 decreases, the bimetal 26 expands from the state shown in the figure, and a plurality of small-diameter pilot valve ports 22 facing each other are sequentially opened from the other end. Thereby, the first orifice 11 is gradually opened, and the pressure in the pressure chamber 10 gradually increases. Then, the piston 16 is gently displaced downward, whereby the valve element 17 is separated from the valve seat 13 to gradually open the main valve port 14 and discharge the low-temperature condensate from the inlet 4 to the outlet 6.

When the low-temperature condensate is discharged and the temperature on the inlet 4 side rises to a desired value, the bimetal 26 narrows to the state shown in the figure, and a plurality of small-diameter pilot valve ports 2 facing each other.
2 is sequentially closed from one end side. Thereby, the first orifice 11 is gradually closed, and the pressure in the pressure chamber 10 gradually decreases through the second orifice 20. Then, the piston 16 is gently displaced upward, and the valve element 17 is seated on the valve seat 13 to gradually close the main valve port 14.

[0013]

The present invention has the following specific effects. As described above, according to the present invention, since the first orifice can be opened and closed with a small deformation force of the temperature sensing member, it is not necessary to increase the size of the temperature sensing member or to combine a plurality of the temperature sensing members. Further, since the first orifice can be opened and closed gradually, a pilot-type steam trap that does not generate water hammer can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a pilot type steam trap according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a pilot valve portion of FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Lid 4 Inlet 5 Condensate sump chamber 6 Outlet 9 Pilot valve 10 Pressure chamber 11 First orifice 14 Main valve port 16 Piston 17 Valve body 18 Valve stem part 20 Second orifice 22 Pilot valve port 26 Bimetal

Claims (1)

[Claims] 1. A pressure chamber partially formed by a pressure-receiving displacement wall of a pressure-responsive valve, a first orifice communicating the pressure chamber to an inlet side, a second orifice communicating the pressure chamber to an outlet side, and a second orifice. A pilot valve that opens and closes a pilot valve port on the inlet side end of one orifice according to the temperature on the inlet side, and operates a pressure responsive valve by controlling the pressure in the pressure chamber by introducing condensate into the pressure chamber. In the above, a pilot valve is formed by a temperature-sensitive member in which a strip-shaped flat plate is curved and one end thereof is fixed, and a plurality of small-diameter pilot valve ports formed from one end to the other end facing the temperature-sensitive member. A pilot type steam trap characterized in that a pressure-responsive valve is operated by sequentially opening and closing a plurality of small-diameter pilot valve ports by deformation of a temperature-sensitive member.