GB2177447A

GB2177447A - Sill for a tank

Info

Publication number: GB2177447A
Application number: GB08615541A
Authority: GB
Inventors: Norman Frank Dewey
Original assignee: Dewey Waters & Co
Current assignee: Dewey Waters & Co
Priority date: 1985-06-28
Filing date: 1986-06-25
Publication date: 1987-01-21
Also published as: GB2177447B; GB8615541D0; GB8516460D0

Abstract

Tanks of the kind which comprise side walls (10) resting on a prepared base (16) with a flexible impermeable membrane (14) extending across the base (16) do not always achieve an effective seal between flanges (12) at the lower end of the side walls (10) and the membrane (14) owing to unevenness in the base (16). The present invention provides a sill (18) which is positioned between the side walls (10) and the base (16), the membrane (14) being sandwiched between the upper face (20) of the sill (18) and the flange (12). The sill has a ramp surface (24) to support the membrane. It is suitably of box or channel section, comprising an upper surface (20) and a lower surface (22) integrally connected by ramp surface (24) and is also provided with a spacer web (18). <IMAGE>

Description

SPECIFICATION Sill for a tank This invention relates to tanks for liquids or the like, of the kind which comprise side walls resting on a prepared base with a flexible impermeable membrane extending across the base and sealed to flanges at the lower edges of the side walls.

A particular problem with tanks of this kind is in obtaining an effective seal between the membrane and the side walls. It is virtually impossible to obtain a really flat base, particularly when made from concrete, which is the usual material. There tend therefore to be gaps between the base and the lower edge flanges of the side wall, through which water can leak.

The present invention provides a tank of the kind described, wherein the membrane is peripherally sandwiched between said side wall flanges and a sill which rests upon the base, the sill having a lower surface adjacent the base, an upper surface cooperating with said side wall flanges to sandwich the membrane, and a ramp surface sloping downwards and inwards with respect to the tank from said upper surface to said lower surface.

The sill is preferably a channel or box section, having spaced apart upper and lower wall which provide said upper and lower surfaces respectively.

The upper and lower walls are preferably joined integrally by a sloping wall which provides said ramp surface. A separate spacer web may be provided between the upper and lower walls remote from the sloping wall. The spacer web is conveniently located in mutually opposed grooves in the upper and lower walls. The upper and lower walls are preferably provided with vertically registering apertures for the purpose of securing the sill to the base by means of bolts or the like.

In order that the invention may be more clearly understood, one embodiment will now be described with referece to the accompanying drawing, which shows a cross-sectional fragmentary view through the base region of a tank.

Referring to the drawing; the tank is formed from wall paneis 10, suitably made from glass fibre reinforced polyester (grp) or the like, joined together edge-to-edge through outturned flanges (not shown). Each wall panel also has an outturned lower flange 12, and the bottom of the tank is closed by means of a flexible water-impermeable membrane 14 which extends across the bottom of the tank and is peripherally sealed to the side wall flanges 12. The tank rests on a prepared concrete base 16, which not only supports the side walls, but also supports the membrane 14 and the weight of water within the tank.

In accordance with the invention, a sill 18 is provided continously around the tank between the side walls and the base. The sill in this embodiment is suitably box-section inform and of extruded aluminium or the like, and comprises an upper wall 20 which lies face-to-face with the side wall flanges 12, a lower wall 22 which lies face-to-face with the base 16, and a sloping wall 24 which is inclined downwardly and inwardly with respect to the tank from the upper wall 20 to the lower wall 22. The membrane 14 is sandwiched between the upper wall 20 of the sill and the side wall flanges 12, and is sealed there by means of a suitable sealing compound compressed by securing nuts and bolts passed through apertures in the flanges 12 and upper wall 20 of the sill.To prove rigidity, a spacer wall 28 is provided between the upper and lower walls 20, 22 in the region remote from the sloping wall 24. The spacer wall is conveniently made separate from the rest of the sill, and can be slid lengthwise into position in mutually facing grooves 30, 32 in ther upper and lower walls 20, 22 respectively. The lower walls 22 of the sill are apertured to receive bolts 34 by means of which the sill is secured to the concrete base 16. These apertures can be in register with the apertures in the top wall 20 and flanges 12 so that the same bolts can be used to clamp the latter together or to facilitate access to the bolts 34 before fitting the side walls to the sill. The sill is conveniently made up from suitable length sections placed end-to-end, and mitred in the corners.

It will be apparentthattheflexible membrane 14 is peripherally sealed between two flat surfaces provided by the flanges 12 of the side walls and the upper wall 20 of the sill, and thus an effective seal should be obtained. Moreover, the sloping surface of the inclined wall 24, suitably at about 45 , enables the membrane to lie smooth and substantially unwrinkled at the bottom of the tank, thereby further minimising the risk of leakage.

The flanges 12 are preferably joined to the upper wall 20 of the sill by bolts 35 separate from those which join the lower wall 22 of the sill to the concrete base. In this way, the sill can be secured to the base and levelled before fitting the side wail panels.

1. tank of the kind in which side walls are supported by a prepared base and a flexible impermeable membrane extends across the base, and is sealed to flanges at the lower edges of the side walls; the membrane being peripherally sandwiched between said side wall flanges and a sill which rests upon the base, the sill having a lower surface adjacent the base, an upper surface cooperating with said side wall flanges to sandwich the membrane, and a ramp surface sloping downwards and inwards with respect to the tank from said upper surface to said lower surface.

2. A tank according to claim 1, wherein the sill is a channel or box-section having spaced apart upper and lower walls which provide the upper and lower surfaces respectively.

3. Atank according to claim 2, wherein the upper and lower walls of the sill are joined integrally by a sloping wall which provides said ramp surface.

4. A tank according to claim 2 or claim 3, wherein a spacer web is provided between the upper and lower walls remote from the sloping wall.

5. A tank according to claim 4, wherein the spacer web is located in mutually opposed grooves in the upper and lower walls.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Sill for a tank This invention relates to tanks for liquids or the like, of the kind which comprise side walls resting on a prepared base with a flexible impermeable membrane extending across the base and sealed to flanges at the lower edges of the side walls. A particular problem with tanks of this kind is in obtaining an effective seal between the membrane and the side walls. It is virtually impossible to obtain a really flat base, particularly when made from concrete, which is the usual material. There tend therefore to be gaps between the base and the lower edge flanges of the side wall, through which water can leak. The present invention provides a tank of the kind described, wherein the membrane is peripherally sandwiched between said side wall flanges and a sill which rests upon the base, the sill having a lower surface adjacent the base, an upper surface cooperating with said side wall flanges to sandwich the membrane, and a ramp surface sloping downwards and inwards with respect to the tank from said upper surface to said lower surface. The sill is preferably a channel or box section, having spaced apart upper and lower wall which provide said upper and lower surfaces respectively. The upper and lower walls are preferably joined integrally by a sloping wall which provides said ramp surface. A separate spacer web may be provided between the upper and lower walls remote from the sloping wall. The spacer web is conveniently located in mutually opposed grooves in the upper and lower walls. The upper and lower walls are preferably provided with vertically registering apertures for the purpose of securing the sill to the base by means of bolts or the like. In order that the invention may be more clearly understood, one embodiment will now be described with referece to the accompanying drawing, which shows a cross-sectional fragmentary view through the base region of a tank. Referring to the drawing; the tank is formed from wall paneis 10, suitably made from glass fibre reinforced polyester (grp) or the like, joined together edge-to-edge through outturned flanges (not shown). Each wall panel also has an outturned lower flange 12, and the bottom of the tank is closed by means of a flexible water-impermeable membrane 14 which extends across the bottom of the tank and is peripherally sealed to the side wall flanges 12. The tank rests on a prepared concrete base 16, which not only supports the side walls, but also supports the membrane 14 and the weight of water within the tank. In accordance with the invention, a sill 18 is provided continously around the tank between the side walls and the base. The sill in this embodiment is suitably box-section inform and of extruded aluminium or the like, and comprises an upper wall 20 which lies face-to-face with the side wall flanges 12, a lower wall 22 which lies face-to-face with the base 16, and a sloping wall 24 which is inclined downwardly and inwardly with respect to the tank from the upper wall 20 to the lower wall 22. The membrane 14 is sandwiched between the upper wall 20 of the sill and the side wall flanges 12, and is sealed there by means of a suitable sealing compound compressed by securing nuts and bolts passed through apertures in the flanges 12 and upper wall 20 of the sill.To prove rigidity, a spacer wall 28 is provided between the upper and lower walls 20, 22 in the region remote from the sloping wall 24. The spacer wall is conveniently made separate from the rest of the sill, and can be slid lengthwise into position in mutually facing grooves 30, 32 in ther upper and lower walls 20, 22 respectively. The lower walls 22 of the sill are apertured to receive bolts 34 by means of which the sill is secured to the concrete base 16. These apertures can be in register with the apertures in the top wall 20 and flanges 12 so that the same bolts can be used to clamp the latter together or to facilitate access to the bolts 34 before fitting the side walls to the sill. The sill is conveniently made up from suitable length sections placed end-to-end, and mitred in the corners. It will be apparentthattheflexible membrane 14 is peripherally sealed between two flat surfaces provided by the flanges 12 of the side walls and the upper wall 20 of the sill, and thus an effective seal should be obtained. Moreover, the sloping surface of the inclined wall 24, suitably at about 45 , enables the membrane to lie smooth and substantially unwrinkled at the bottom of the tank, thereby further minimising the risk of leakage. The flanges 12 are preferably joined to the upper wall 20 of the sill by bolts 35 separate from those which join the lower wall 22 of the sill to the concrete base. In this way, the sill can be secured to the base and levelled before fitting the side wail panels. CLAIMS

6. A tank according to any one of claims 2 to 5, wherein the upper and lower walls are provided with vertically registering apertures for the purpose of securing the sill to the base by means of bolts or the like.

7. A tank substantially as described herein with reference to the drawing.

8. A sill for a tank of any one of the preceding claims.