JP2884293B2 - Pilot type steam trap - Google Patents

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, and more particularly, to a pressure trap operated by a pilot float which rises and falls according to a liquid level at an inlet side. The present invention relates to a pilot-type steam trap that is driven to open and close a main valve port communicating an inlet and an outlet.

[0002]

2. Description of the Related Art A conventional pilot type steam trap will be described with reference to Japanese Patent Publication No. 53-26848. This includes a trap casing that forms an inlet, a condensate sump and an outlet, a pressure-responsive valve that opens and closes a main valve opening that communicates the condensate sump and the outlet, an upper part that communicates with the condensate sump, and A pilot chamber provided with a pilot chamber having a lower communication path and a pilot path communicating with a pressure chamber partially formed by a pressure receiving displacement wall of the pressure responsive valve; By opening and closing the pilot passage with a pilot float that rises and falls according to the liquid level, the pressure responsive valve is operated.

[0003]

In the above apparatus, the pilot float and the pressure responsive valve frequently open and close repeatedly, and the valve mechanism of the pilot float and the pressure responsive valve are damaged in a short time due to wear or the like. There was an inoperable problem.
Because the float chamber communicates with the condensate chamber through the upper and lower communication passages, the liquid level in the float chamber rises with the rise in the liquid level in the condensate sump chamber. In this case, the pilot valve opens the pilot passage early, so that the pressure-responsive valve opens the main valve port early.

Accordingly, it is an object of the present invention to prevent the pilot float and the pressure-responsive valve from frequently opening and closing.

[0005]

The technical means of the present invention taken to solve the above technical problems is a trap casing forming an inlet, a condensate sump and an outlet, and a condensate sump. A pressure responsive valve that opens and closes a main valve port that communicates with the outlet and an upper and lower communication passage that communicates with the condensate sump chamber, and a pressure chamber partially formed by a pressure receiving displacement wall of the pressure responsive valve. A pilot float disposed in a float chamber having a communicating pilot passage, and operating the pressure responsive valve by opening and closing the pilot passage with the pilot float floating and descending according to the liquid level in the float chamber. In this case, the lower communication path is closed at a position where the pilot flow closes the pilot path.

[0006]

The operation of the above technical means is as follows.
Because the pilot float closes the lower communication passage at the position where the pilot passage is closed, water is returned to the float chamber through the upper communication passage after the liquid level in the condensate sump reaches the upper communication passage. Will flow in. Therefore, by delaying the inflow of the condensate into the float chamber, the opening of the pilot passage by the pilot float and the opening of the main valve port by the pressure responsive valve can be delayed. Frequent opening and closing of the response valve can be prevented.

[0007]

A first embodiment showing a specific example of the above technical means will be described (see FIG. 1). The trap casing 1 forms the inlet 2, the valve chamber 3 and the outlet 4. The valve chamber 3 is partitioned by a partition tube 5 into a condensate sump chamber 6 on the inlet 2 side and a chamber in which the following pressure responsive valve 9 on the outlet 4 side is arranged. Inlet 2 and Exit 4
Communicates through a main valve port 7 formed at the lower end of the partition tube 5 and a window 8 formed above the main valve port 7.

A pressure responsive valve 9 for opening and closing the main valve port 7 is disposed in the partition tube 5. The pressure-responsive valve 9 includes a cylindrical main valve body 11 having a top wall 10 and a connecting rod 13 penetrating a partition wall 12.
And a piston 14 as a pressure-receiving displacement wall connected via a pressure-sensitive member. The main valve body 11 opens and closes the main valve port 7 at the lower end from the outlet 4 side. A seal ring 15 is provided between the outer periphery of the top wall 10 of the main valve body 11 and the partition tube 5, a seal ring 16 is provided between the outer periphery of the connecting rod 13 and the partition wall 12, and a seal ring 16 is provided between the outer periphery of the piston 14 and the partition tube 5. A seal ring 17 is arranged between them.

A pressure equalizing chamber 18 is formed between the top wall 10 of the main valve body 11 and the partition wall 12, and a pressure chamber 19 is formed between the partition wall 12 and the piston 14. The pressure equalizing chamber 18 communicates with the inlet 2 side by a pressure equalizing passage 20 penetrating the top wall 10. The pressure chamber 19 has the following flow through a pilot passage 21.
In addition to communicating with the outlet chamber 27, it communicates with the outlet 4 through a small hole 22 having a smaller diameter than the pilot passage 21. An upper space 23 of the piston 14 communicates with the outlet 4 side by an outlet passage 24. The pressure responsive valve 9 is urged in the valve closing direction by a coil spring 25 as an elastic member disposed in the upper space 23.

A float chamber 27 in which the pilot passage 21 is opened is formed above the condensate sump chamber 6 with a partition 26 therebetween. The float chamber 27 communicates with the pressure chamber 19 through a pilot passage 21 provided at a lower portion, and an upper communication passage 28 provided at an upper portion and a lower communication passage 29 provided at a lower end.
Thereby, it communicates with the condensate sump chamber 6. A spherical pilot float 30 is placed in the float chamber 27 in a free state.
The pilot float 30 floats and descends according to the liquid level in the float chamber 27 to open and close the pilot passage 21 and the lower communication passage 29.

The main valve body 11 has an area on the lower surface side where the fluid pressure on the inlet 2 acts in the valve opening direction and an area on the upper surface side where the fluid pressure on the inlet 2 acts in the valve closing direction through the equalizing passage 20. Are formed identically to cancel out the force due to the fluid pressure.

The operation of the above embodiment is as follows. When the amount of condensed water flowing from the inlet 2 is small or not present, the pilot float 30 descends to block the pilot passage 21. The pressure in the pressure chamber 19 acting on the upper and lower sides of the piston 14 and the pressure in the upper space 23 are both the pores 22 and the outlet passage 2.
Since the pressure is made equal to the pressure at the outlet 4 through the four passages, the pressure responsive valve 9 is urged downward by the elastic force of the coil spring 25, and the main valve body 11 closes the main valve port 7. Next, when a large amount of condensate flows in from the inlet 2, the condensate is collected in the condensate sump chamber 6, and after the liquid level reaches the upper communication passage 28,
Flows into the float chamber 27 from As the liquid level in the float chamber 27 rises, the float 30 floats and opens the pilot passage 21 and the lower communication passage 29. As the pressure in the pressure chamber 19 rises, the pressure responsive valve 9 is displaced gently upward while opposing the elastic force of the coil spring 25, and the main valve body 11 gently opens the main valve port 7 with this. The condensate from the inlet 2 is discharged to the outlet 4. When the liquid level in the condensate sump chamber 6 and the float chamber 27 decreases due to the discharge of the condensate water, the float 30 descends and closes the pilot passage 21 and the lower communication passage 29. Since the pressure in the pressure chamber 19 gradually decreases through the small holes 22, the pressure-responsive valve 9 is gradually displaced downward by the elastic force of the coil spring 25, and the main valve body 11 is moved to the main valve port 7.
And close the valve.

[0013]

The present invention has the following specific effects. As described above, according to the present invention, frequent opening / closing of the pilot float and the pressure responsive valve can be prevented by closing the lower communication passage at the position where the pilot float closes the pilot passage, and the valve mechanism is improved. It will not be damaged early.

[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.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Trap casing 2 Inlet 4 Outlet 6 Condensate sump room 7 Main valve port 9 Pressure response valve 19 Pressure chamber 21 Pilot passage 27 Float chamber 28 Upper communication passage 29 Lower communication passage 30 Float

Claims (1)

(57) [Claims] 1. A trap casing that forms an inlet, a condensate sump and an outlet, a pressure responsive valve that opens and closes a main valve opening communicating the condensate sump and the outlet, and a communication with the condensate sump. A pilot float arranged in a float chamber having an upper and lower communication passage and having a pilot passage communicating with a pressure chamber partially formed by a pressure receiving displacement wall of the pressure responsive valve; The pilot responsive valve is operated by opening and closing the pilot passage with the pilot float that rises and falls according to the liquid level of the pilot chamber. In the pilot float, the lower communication passage is closed at the position where the pilot passage is closed. A pilot type steam trap characterized by the following.