BACKFLOW PREVENTION APPARATUS

Title:

BACKFLOW PREVENTION APPARATUS

Document Type and Number:

WIPO Patent Application WO/2016/043143

Kind Code:

A1

Abstract:

[Problem] The present invention provides a backflow prevention apparatus for the purpose of preventing a backflow of drainage while also cutting off the flow of gas. [Solution] The backflow prevention apparatus (1) comprises a check valve (10) and a float-type backflow prevention valve (20) provided in order from upstream to downstream. The check valve (10) comprises: a valve seat (15) connecting the upstream side of a drainage system with the float-type backflow prevention valve (20) side; a valve body (14) that closes the valve seat (15) with an upward biasing force and that opens the valve (15) by dropping against a biasing force engendered by a water load of drainage entering from the upstream side; and a biasing means (13) that biases the valve body (14) upwardly, wherein the components needed for the valve body (14) to close the valve seat (15), including the valve seat (15), the valve body (14), and the biasing means (13), are formed from a metal. The float-type backflow prevention valve (20) comprises: an annular valve seat (21) that connects the check valve (10) side and the downstream side of the drainage system; a float (24) that rises in accordance with rises in the water level of the drainage to close the annular valve seat (21) and that sinks in accordance with drops in the water level of the drainage to open the annular valve seat (21); a guide member (22) that guides the movement of the float (24) in the up/down direction; and a restriction member (23) that restricts the lowest position of movement of the float (24).

Inventors:

NISHIYAMA TOSHIMASA (JP)

Application Number:

PCT/JP2015/075941

Publication Date:

March 24, 2016

Filing Date:

September 14, 2015

Export Citation:

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Assignee:

TLV CO LTD (JP)

International Classes:

F16K15/06; E03F7/04; F16K31/18

Foreign References:

JP2002524674A	2002-08-06
JPH0667588U	1994-09-22
JPH1182771A	1999-03-26
JP2000240846A	2000-09-08

Other References: