Flood valve

A flood valve adapted to close an opening through a barrier wall separating a fluid from a space, the valve having a plastic body with a bore therethrough, a piston slidable in the bore, a heating element carried by the body and having a section extending across the bore to restrain the piston against movement out of the bore, and a spring urging the piston against the restraining section of the heating element, the piston normally sealing the bore and the heating element, when energized, burning through the plastic body material to release the piston for admission of fluid through the bore to the space.

SUMMARY OF THE INVENTION 
This invention relates generally to the valve art, and more particularly to 
an improved flood valve of the electro-thermal type which can be 
selectively operated to permit the passage of fluid therethrough. 
A primary object of this invention is to provide a flood valve which is 
very simple in construction, relatively inexpensive, extremely reliable 
and totally quiet in operation. 
The flood valve of this invention uses an electric heating element to melt 
a portion f a tubular plastic body member to release a sealing piston. It 
is characterized by the heating element also being a restraining member 
normally holding the sealing piston in the bore of the valve body. Upon 
energizing the heating element, it melts its way through the plastic 
material of the body member, releasing itself and thereby freeing the 
piston to move out of the bore and open the same for the passage of fluid. 
The foregoing and additional objects, advantages and characterizing 
features of this invention will become apparent from the ensuing detailed 
specification of an illustrative embodiment thereof, reference being made 
to the accompanying drawing wherein like reference numerals denote like 
parts throughout the various views.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT 
Referring to the accompanying drawing, there is shown a flood valve of this 
invention generally designated 10, the valve being positioned in an 
opening through a barrier wall 11 separating a fluid on one side of the 
wall from a relatively unpressurized space on the other side thereof. 
Flood valve 10 is of general utility, and can be employed in a variety of 
arrangements where it is desired to separate fluid, either a gas or 
liquid, from a relatively unpressurized space until such time as 
communication therebetween is to be effected. For example, the valve can 
be used to selectively admit fluid to a chamber, or to selectively permit 
the escape of fluid from a chamber. Normally, valve 10 closes the opening 
through wall 11, as shown in FIG. 1, while being selectively activated to 
open the communicating passageway and permit fluid to pass through the 
wall from one side to the other side thereof, this being the condition 
illustrated in FIG. 2. 
Looking now at FIG. 1, valve 10 includes a body member 12 of one piece 
construction having threaded engagement in an opening 13 through wall 11, 
the wall separating fluid, under pressure, for example water, on its side 
14 from a relatively unpressurized space on the side 15 of wall 11. Body 
member 12 is formed at its forward end portion with an enlarged head 16 
exposed to the pressure fluid. Head 16 has sealing engagement against side 
14 of wall 11, and can be provided with slots 17 to receive a torque 
wrench for firmly seating flood valve 10 in the wall opening. A seal, not 
shown, can be provided between head 16 and wall 11. 
Body member 12 is formed with an internal bore 18 extending completely 
therethrough, bore 18 being of cylindrical configuration and of reduced 
diameter at the forward end portion to provide an internal shoulder 19 
within head 16, and being adapted to provide an open fluid passageway 
completely through the valve in a manner to be described. 
Initially, however, the passageway defined by the wall of bore 18 is closed 
by a plug in the form of a piston assembly 20 having sliding clearance 
within bore 18. Piston assembly 20 includes a one-piece member of solid 
circular section formed at its forward end with a head 21 connected to a 
heavier rearward end section 22 of greater axial length by a reduced 
diameter neck 23 defining a circumferential groove receiving an O-ring 24 
having sealing engagement against both the piston member and the wall of 
bore 18, for effectively sealing the bore passage. Head 21 and end 22 have 
sliding clearance with the wall of bore 18. 
The rearward end portion 25 of valve 10 extends into the relatively 
unpressurized space and is of reduced diameter compared to the externally 
threaded intermediate body portion engaged in wall 11, to facilitate the 
insertion of the flood valve into the wall opening. Body member 12 is of 
annular configuration, and diametrically opposed holes or openings 26 are 
formed through rearward end portion 25, spaced from but closely adjacent 
the extreme inner or rearward end 27 of body member 12. A heating element 
in the form of Nichrome or other electrical heating wire 28 is threaded 
through openings 26, extending across the end of piston assembly 20, and 
it is a particular feature of this invention that the heating element also 
is a retainer, holding piston assembly 20 against movement out of bore 18. 
Externally of body member 12, wire 28 is held closely together by a 
two-hole insulator 29, thereby defining a wire loop confined in openings 
26 and blocking the piston assembly 20. Heating wire 28 is enveloped in a 
high temperature sleeve 30 of insulating material and leads to an 
electrical connector 31 of conventional design, adapted for connection to 
a source of electricity at a remote point. 
Fluid under pressure on the side 14 of wall 11 will act against piston 
assembly 20 urging it through bore 18 in the direction of end 27. In 
addition, coil spring 32 can be positioned within bore 18, bearing at one 
end against shoulder 19 and at its opposite end against the head portion 
21 of piston assembly 20, thereby also urging piston assembly 20 in the 
direction of the rearward portion of the valve. The use of spring 32 
insures a snug, tight assembly and is preferred 
Piston assembly 20 also includes a heat shield 36, which can be in the form 
of a thin, circular disk of ceramic material, positioned between section 
22 and heating wire section 33, the heat shield protecting section 22 of 
the piston from the melting action of the heating element. 
Normally, piston assembly 20 is restrained by the heating element 28, and 
particularly the section 33 thereof which extends through openings 26 and 
across the end face of heat shield 36. In this condition shown in FIG. 1, 
piston assembly 20 is retained within valve 10 by the heating element and 
effectively seals bore 18, maintaining the fluid on side 14 of wall 11 out 
of communication with the relatively unpressurized space on side 15 of 
that wall. 
When it is desired to admit fluid into the relatively unpressurized space, 
the electrical connection to heating element 28 is activated by any 
suitable means, which can be entirely conventional, for energizing the 
wire 28 in response to any preselected action or signal. Upon 
energization, wire 28 heats up almost instantly, and because of its high 
resistance, quickly reaches an elevated temperature above the melting 
temperature of the material of which body member 12 is made. This can be 
any suitable plastic material, with polyvinyl chloride being an excellent 
example, which will melt at a relatively low temperature while maintaining 
its integrity under temperature conditions encountered during normal use. 
However, upon passing current through wire 28, causing it to heat up, wire 
28 rapidly burns its way through the material of body member section 34 
between openings 26 and the extreme end 27 of the body member. Spring 32, 
and the pressure fluid, will continue to force piston assembly 20 and its 
heat shield 36 against the restraining section 33 of heating element 28 as 
it burns its way through body section 34, constantly urging it against the 
plastic material still holding the heating element section 33 within the 
body member, until it has burned completely through, leaving grooves 35 
from openings 26 through section 34 to the inner end 27 of the valve body. 
Once the retaining section 33 of heating element 28 has burned through the 
body member, both it and piston assembly 20 are released, with the piston 
assembly and its heat shield being expelled from bore 18 by the combined 
action of spring 32 and the pressure fluid, whereupon fluid passes into 
the relatively unpressurized space through the open ended bore 18 of the 
flood valve. 
Piston member 21, 22, 23 also can be of any suitable plastic material, 
preferably having a higher melting point than the PVC body material, for 
example Teflon. This, in conjunction with heat shield 36, insures the 
continued integrity of the piston assembly as the heating element melts 
its way through the body material to open the valve. 
From the foregoing, it is seen that the flood valve of this invention 
accomplishes its intended objects. It is a very simple and relatively 
inexpensive construction, readily molded, formed and assembled. Body 
member 12 and piston member 21, 22, 23 each can be molded as a one-piece 
member of suitable plastic material, openings 26 are drilled through the 
wall of member 12 and heating element 28 is quickly threaded therethrough. 
At the same time, valve 10 is highly dependable, extremely fast-acting, 
silent in operation, and can be activated from a remote point. 
While a specific embodiment has been shown and described in detail, it will 
be appreciated that this has been done by way of example only and that the 
invention is intended to be defined by the appended claims.