JP4800093B2 - Pilot steam trap - Google Patents

Description

  The present invention relates to a steam trap that discharges condensate generated in a steam piping system, and in particular, a pilot that opens and closes a main valve port by driving a main valve body by a pressure responsive member that is displaced by opening and closing of an auxiliary pilot valve. Regarding the steam trap.

This pilot type steam trap is disclosed in, for example, Japanese Utility Model Publication No. 4-42997. This forms the inlet and the valve chamber and the outlet in the trap housing, the float is a main valve body for opening and closing a main valve port which communicates the valve chamber and the outlet, the pilot valve port by the pilot float is a pilot valve of the auxiliary Opening and closing control is performed by a pressure responsive member that is displaced by opening and closing, and when the pilot float rises and opens the pilot valve port, the pressure responsive member is driven upward to lift the float and open the main valve port. When the pilot valve port is closed and the pilot valve port is closed, the pressure responsive member is pushed downward by the weight of the float, and the float closes the main valve port .

In the above-described conventional pilot steam trap, if the pilot float fails and cannot be closed, and the steam leaks into the pilot passage, the float is opened by the pressure responsive member and the main valve port cannot be closed. Therefore, there is a problem that a large amount of steam leaks from the main valve port.

Therefore, the technical problem of the present invention is to provide a pilot-type steam trap that allows the float to open and close the main valve port even when the pilot float fails and cannot be closed.

Technical means of the present invention taken in order to solve the technical problems described above, to form an inlet and the valve chamber and the outlet in the trap housing, in the main valve body for opening and closing a main valve port which communicates the valve chamber and the outlet A float is controlled to open and close by a pressure responsive member that is displaced by opening and closing the pilot valve port by a pilot float that is an auxiliary pilot valve . When the pilot float rises and opens the pilot valve port , the pressure responsive member moves upward. When the float is lifted to open the main valve port, the pilot float descends and the pilot valve port is closed, the pressure responsive member is pushed downward by the weight of the float, and the float closes the main valve port . the pilot passage connecting the pilot float and the pressure responding member, closed at a high temperature by the steam leakage open pilot passage at a low temperature It is obtained by disposing the temperature-sensitive responsive valve.

The present invention produces an excellent effect that a large amount of steam is not leaked because the float can open and close the main valve port even when the pilot float fails and cannot be closed.

In the present invention, a temperature sensitive valve is disposed in a pilot passage connecting a pilot float and a pressure responsive member, and the temperature sensitive valve opens the pilot passage at a low temperature and closes it at a high temperature due to steam leakage. Therefore, if the pilot float fails and cannot be closed, and steam is leaked into the pilot passage, the temperature of the pilot passage becomes high, and the temperature sensitive valve closes the pilot passage. When the pilot passage is closed, the pressure responsive member is displaced in the valve closing direction, and the float closes the main valve port. Thereafter, when the temperature of the pilot passage decreases due to heat radiation, the temperature sensitive valve opens the pilot passage. When the pilot passage is opened, the pressure responsive member is displaced in the valve opening direction, and the float opens the main valve port. Thus, even when the pilot float fails and cannot be closed, the float can open and close the main valve port.

An embodiment showing a specific example of the above technical means will be described (see FIG. 1).
A lid casing 2 is fastened to the main body 1 to form a trap casing having a valve chamber 3 therein. An inlet 4 and an outlet 5 are formed on the same axis at the top of the trap casing. A valve seat 7 having a main valve port 6 communicating with the valve chamber 3 and the outlet 5 is attached to the lower side of the valve chamber 3. A hollow spherical float 8 which is a main valve body for opening and closing the main valve port 6 is accommodated in the valve chamber 3 in a free state.

  A pressure chamber is formed between the valve chamber 3 and the bottom lid 9 separated by a bottom wall. A piston 10 as a pressure responsive member is disposed in the pressure chamber, and the pressure chamber is hermetically partitioned into a first pressure chamber 11 and a second pressure chamber 12. A connecting rod 13 is attached to the upper surface of the piston 10. The distal end of the connecting rod 13 penetrates the bottom wall of the valve chamber 3 in an airtight manner, extends into the valve chamber 3, and contacts the float 8 via the receiving plate 14. The first pressure chamber 11 and the second pressure chamber 12 are connected to each other through a pore 15 opened in the piston 10, and the first pressure chamber 11 is connected to the outlet 5 through an outlet side passage 16.

  A partition wall 18 having an upper end opened in the valve chamber 3 and a communication hole 17 formed in the lower portion is provided, and a hollow spherical pilot float 19 as an auxiliary pilot valve is accommodated in a free state on the inlet 4 side. The pilot float 19 rises and falls together with the liquid level, and opens and closes a pilot valve port 20 formed on the lower side. The pilot valve port 20 and the second pressure chamber 12 are connected via a pilot passage 21. A temperature sensitive responsive valve 22 is disposed in the pilot passage 21.

  As shown in FIG. 2, the temperature sensitive valve 22 includes a temperature sensitive member 41 in a valve chamber 40 formed therein by an upper case 37 having an inlet 36 and a lower case 39 having an outlet 38. Is. The temperature sensing member 41 welds the outer peripheral edges of the upper and lower wall members 42 and 43 and the upper and lower diaphragms 44 and 45, encloses the expansion medium 46 between the upper wall member 42 and the upper diaphragm 44, and The member 47 is welded. The expansion medium 46 is formed of water, a liquid having a lower boiling point than water, or a mixture thereof. The temperature sensing member 41 is urged downward by a spring 48 and presses against the step portion 51 of the housing cylinder 50 having a plurality of passage windows 49. The valve member 47 of the temperature sensing member 41 opens and closes the lead-out path 53 by being seated on the lower valve seat 52. When the pilot float 19 cannot close the pilot valve port 20 and the steam leaks into the pilot passage 21 and the temperature of the pilot passage 21 becomes high, the temperature sensing valve 22 expands the expansion medium 46 and the upper and lower diaphragms. 44 and 45 are displaced toward the valve seat 52, and the valve member 47 closes the lead-out path 53 to close the pilot passage 21. When the temperature of the pilot passage 21 decreases due to heat dissipation, the temperature sensitive valve 22 contracts the expansion medium 46 and displaces the upper and lower diaphragms 44 and 45 away from the valve seat 52, and the valve member 47 opens the outlet passage 53. As a result, the pilot passage 21 is opened.

  When there is little or no condensate flowing in from the inlet 4, the pilot float 19 descends and closes the pilot valve port 20. Since the pressure in the second pressure chamber 12 is released to the outlet 5 side through the pore 15, the piston 10 is pushed downward by the weight of the float 8, the float 8 is seated on the valve seat 7 and the main valve port 6 is closed. Yes. When a large amount of condensate flows from the inlet 4, the pilot float 19 rises as the liquid level rises and opens the pilot valve port 20. When the pilot valve port 20 is opened, the condensate on the inlet 4 side is supplied to the second pressure chamber 12, the pressure in the second pressure chamber 12 rises, the piston 10 is driven upward, and the float 8 is lifted. The main valve port 6 is opened and the condensate is discharged to the outlet 5. When the liquid level decreases due to the discharge of the condensate, the pilot float 19 descends with the liquid level decreasing and closes the pilot valve port 20. When the pilot valve port 20 is closed, the pressure in the second pressure chamber 12 is released to the outlet 5 side through the pore 15, the piston 10 is pushed downward by the weight of the float 8, and the float 8 is seated on the valve seat 7. Close the main valve port 6.

  The temperature sensitive valve 22 closes the pilot passage 21 when the pilot float 19 cannot close the pilot valve port 20 and the steam leaks into the pilot passage 21 and the temperature of the pilot passage 21 becomes high. When the pilot passage 21 is closed, the pressure in the second pressure chamber 12 is released to the outlet 5 side through the pore 15, so that the piston 10 is pushed downward by the weight of the float 8 and the float 8 is seated on the valve seat 7. Close the main valve port 6. The temperature sensitive responsive valve 22 opens the pilot passage 21 when the temperature of the pilot passage 21 decreases due to heat radiation. When the pilot passage 21 is opened, the condensate on the inlet 4 side is supplied to the second pressure chamber 12, the pressure in the second pressure chamber 12 rises, the piston 10 is driven upward, and the float 8 is lifted. The main valve port 6 is opened and the condensate is discharged to the outlet 5.

It is sectional drawing of the pilot type steam trap of the Example of this invention. It is sectional drawing of the temperature sensitive responsive valve used for the pilot type steam trap of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body 2 Lid member 3 Valve chamber 4 Inlet 5 Outlet 6 Main valve port 8 Float 10 Piston 11 First pressure chamber 12 Second pressure chamber 19 Pilot float 20 Pilot valve port 21 Pilot passage 22 Temperature sensitive valve

Claims (1)

The trap casing forms the inlet, valve chamber, and outlet, and the float that is the main valve body that opens and closes the main valve port that connects the valve chamber and the outlet is displaced by opening and closing the pilot valve port with the pilot float that is the auxiliary pilot valve When the pilot float rises and opens the pilot valve port, the pressure responsive member is driven upward to lift the float, open the main valve port, and the pilot float descends. When the pilot valve port is closed, the pressure responsive member is pushed downward by the weight of the float, and the float closes the main valve port.In the pilot passage that connects the pilot float and the pressure responsive member, the pilot passage is opened at low temperatures. Pilot-type steam valve with a temperature sensitive valve that closes at high temperature due to steam leakage -Up.

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