IES20060427A2 - Improved flue pipes - Google Patents

Abstract

A flue pipe if provided in sections (10,20). Male end (11) of section (10) inter engages with female end (21) of section (20). Complementary engaging formations (14,24) are provided on male end (11) and female end (21). When engaged these formations (14,24) enable the two sections to retate relative to one another when engages. <Figure 2a>

Description

The present invention relates to improvements to flue pipes, in particular stainless steel flue pipes.

Flue pipes particularly stainless steel flue pipes come in many designs and may be single wall or double wall pipes for solid fuel, oil or gas fired heating installations.

A typical prior art single wall stainless steel flue system is a factory-made single-wall flue system offering a high level of single wall performance. The system comprises straight lengths, bends, tees and a full range of accessories and non standard adaptors so that it is possible to connect the pipe to any boiler or chimney system.

Such flue pipes are available in four standard diameters from 125mm (5”) to 205mm (8”), with larger sizes also possible.

The typical single wall system is suitable for closed solid fuel appliances. It is mainly used for re-lining existing chimneys but can also be used in short runs from an appliance to an existing flue.

All lengths and flue gas carrying fittings of the typical single wall system are made from 0.4mm to 1mm thick, 316 grade stainless steel. The pipe seams are lockformed and rolled which produces an excellent gas sealed joint and offers minimum resistance to flue gas flow. A press fit jointing system can be used which provides structural stability. It is recommended that a chimney is backfilled with a granular insulation material.

The typical prior art single wall stainless steel flue system operates most efficiently where there is a vertical run from the appliance to the terminal. A selection of bends is available to provide an offset from the vertical whenever a straight route is not possible. The chimney should not make an angle of more than 30° with the vertical for solid fuel appliances, except where the flue is connected to the outlet of the appliance. The flue diameter should not be smaller than that of the outlet of the appliance. Access to the chimney for cleaning and inspection purposes may be provided with either a plugged tee located at the base of the chimney where it begins its vertical run, or a bend with a gas tight access door.

IE 06 0 427 The typical prior art single wall stainless steel flue system components are assembled by press fitting the crimped and swaged male end into the uncrimped female end. The male end should be facing downwards to facilitate drainage of any condensate formed inside the flue.

The typical prior art single wall stainless steel flue system is suitable for re-lining chimneys, which do not contain combustible materials. It should not be used in close proximity to any combustible materials.

There is also available in the prior art a factory-made twin-wall insulated stainless steel flue system offering a very high level of performance. The system ensures a stable draught and a low external surface temperature which makes the system suitable for both internal or external use. The system also comprises straight lengths, bends, tees and a full range of accessories and non-standard adaptors so that it is possible to connect to any boiler or chimney system. They are generally available in four standard diameters from 125mm (5”) to 205mm (8”), with larger sizes also possible.

The typical double wall system can be used internally or externally as an independent chimney system, and is suitable for gas, oil and solid fuel burning appliances. It has been designed for flue gas temperatures of up to 540°C under normal operating conditions and will withstand higher temperatures up to 1100°C for a short period of time, such as might occur in the event of a chimney fire.

The typical prior art double wall system is made from three distinct materials. The combination of the three materials yields a product with a high thermal resistance, quick stabilisation of the flue gas temperature and the existence of a strong draught, all of which help to prevent the formation of harmful condensation in the flue. The outer body is made from 0.5mm, 304 grade stainless steel and carries the structural load. It has a bright polished finish and is completely weatherproof. The inner lining is made from 0.4mm 316 grade stainless steel and is free to expand or contract as the flue gas temperatures change. The material is resistant to the corrosive elements produced during combustion. The space between the inner liner and the outer body contains a Kaowool thermal ceramic blanket. The liner and body seams are lockformed and rolled which produces an excellent gas sealed joint and offers minimum resistance to flue gas flow. All components have specially crimped and swaged ends, which, together with a ceramic IE 0 6 0 4 27 gasket and a locking band with a built in toggle clasp, provide both strength and gas tightness to the flue.

The prior art double wall system operates most efficiently where there is a vertical run 5 from the appliance to the terminal. A selection of bends is available to provide an offset from the vertical whenever a straight route is not possible. No part of a chimney should form an angle with the vertical of more than 30° for solid fuel appliances or 45° for oil or gas appliances. The only exception to this is when connecting the flue system to the appliance. The inner liner diameter should not be smaller than that of the outlet of the appliance. A gas tight access door should be installed in the flue system for inspection and cleaning purposes. This may be provided with either a plugged tee located at the base of the chimney where it begins its vertical run, or a bend with a gas tight access door.

The prior art double wall system components are assembled by press fitting the components together. Joints are secured with a locking band, complete with toggle latch, which fits over the swages on the ends of the two components. Components are always fitted together with the crimped male end of the liner facing downwards.

With the typical prior art double wall system there must be a minimum distance of 50mm to combustible materials from the flue. However, if the chimney passes through a floor or ceiling, then clearances at floor and ceiling joists must be established using a telescopic fire stop. Where the chimney passes through the roof, a roof centring plate should be used. In addition the chimney should be installed to ensure that no joints occur between floors.

Under no circumstances should the weight of the chimney be transmitted to the appliance. Inside a building, the weight of the chimney must be borne by either a base wall support, an intermediate wall support or a telescopic fire stop. The telescopic fire stop rests on the ceiling joists thus bearing the load of the chimney at ceiling level. Externally, the chimney should be attached to a wall or else supported by a mast. Base wall supports should be used where the chimney begins its vertical run. Intermediate wall supports should be used to support the chimney along its vertical run. Where the chimney extends by 1.5m or more above the last support it should be supported by guy wires which are attached to the chimney with guy wire brackets. Adjustable lead flashings are available for flat and IE 060 427 pitched roofs. A storm collar must be fitted to the flue immediately above the lead flashing, and the joint should be sealed with a waterproof sealant A stainless steel terminal is used for solid fuels and oil and a special gas cowl can also be attached.

The constraints within chimneys or getting access to spaces for installing flue pipes means that it is not always possible to get an ideal vertical run. Installing any deviation for the vertical, such as bends, double bends, complex bends, right angles, cowls and caps, means that the fitting of the components together can be slow and labourious in order for all the components to be manoeuvred and fitted together in a manner which provides a flue gas tight seal.

The object of the invention is to provide an improved flue pipe which can alleviate the above disadvantages.

The present invention provides a flue pipe which is provided in elongate sections with a first end of one section being engageable in a second end of a second section, with the first and second ends being provided with complementary engageable formations enabling relative rotation of one section relative to the second section when engaged.

Advantageously, the first end is a male end and the second end is a female end with a twist lock dimple being provided on the male end and a complementary shaped receiver for the dimple on the female end.

Conveniently, there are at least two twist lock dimples on the male end and there are a complementary number of receivers on the female end.

Preferably, the twist lock dimples and receivers are located in a non-symmetrical manner about the surface of the pipe sections whereby the ends of the section can only interengage and disengage in one relative position.

Conveniently, a sealing element is provided between the two ends.

If required a locking clamp may also be provided between the two ends.

Advantageously, the flue pipe sections are seam welded.

IE 060 427 The invention will hereinafter be more particularly described with reference to the accompanying drawings, which show, by way of example only an embodiment of a flue pipe according to the invention. In the drawings: Figure 1 is a side view showing a range of typical flue pipe installations; Figure 2A is a perspective view of a male end and a female end of two flue pipe sections prior to engagement; Figure 2B is a perspective view of the two ends approaching mutual engagement; Figure 2C is a perspective view of the two ends mutually engaged; Figure 2D is a perspective view of the two ends engaged after relative rotation; Figure 3 is a cross-sectional side view of a twin walled flue pipe mutually engaged by means of the invention and showing two possible locking brackets which are further exemplified in Figure 4A, 4B, 4C and 4D and Figure 5; Figure 6 is a cross-sectional side view of a single wall pipe in accordance with the invention.

Referring to the drawings, Figure 1 illustrates a number of flue pipe installations and which shows the variations of flue pipe arrangement which a flue pipe manufacturer must provide for making different sections.

The invention is particularly demonstrated and shown in Figures 2A to 2D. Two sections of seam welded flue pipe 10 and 20 are shown being engaged together. Male end 11 of section 10 inter-engages with female end 21 of the section 20. The male end 11 has a formed collar 12, a locating dimple 13 on the collar 12 and a pair of twist lock dimples 14 (only one of which is visible in the drawing). The female end 21 is swaged to accommodate the male end 11 as far as the collar 12 and has a locating dimple 23 and a pair of receivers 24 which can accommodate the pair of twist lock dimples 14 and thereby provide the complementary engagable formations 14, 24 of the invention. The formations 14, 24 are not diametrically opposite to one another so that there is only one position IE 0 60 427 through 360 degrees rotation that the formations 14, 24 can align and thus inter-engage. To assist the user to locate the correct position for inter-engagement, all that is necessary for the user is to align the locating dimples 13 and 23. When the two ends 11 and 21 are engaged as shown in Figure 2C, one end may be rotated relative to the other as shown in Figure 2D in order to prevent the two ends from separating from one another. A separate section (not shown) may be located with the inner surface of formed collar 25.

In order to fully secure both ends together use may be made of locking collar 30 or the shorter locking collar 31, both which are shown in Figures 3 to 5.

With the use of this invention, it is possible to rotate one section through 360 degrees if necessary in order to enable proper alignment of the various sections some of which will have bends, angles and turns as required. This will greatly facilitate the assembly of flue pipes in situ.

It is to be understood that the invention is not limited to the specific details described here which are given by way of example only and that various modification and alterations are possible without departing from the scope of the invention.

Claims (5)

CLAIMS:

1. A flue pipe which is provided in elongate sections with a first end of one section being engageable in a second end of a second section, with the first and second ends 5 being provided with complementary engageable formations enabling relative rotation of one section relative to the second section when engaged.

2. A flue pipe as claimed in Claim 1 in which the first end is a male end and the second end is a female end with a twist lock dimple being provided on the male end and a 10 complementary shaped receiver for the dimple on the female end.

3. A flue pipe as claimed in Claim 2 in which there are at least two twist lock dimples on the male end and there are a complementary number of receivers on the female end and 15 optionally in which the twist lock dimples and receivers are located in a nonsymmetrical manner about the surface of the pipe sections, whereby the ends of the section can only inter-engage and disengage in one relative position.

4. A flue pipe as claimed in any one of the preceding claims in which a sealing 20 element is provided between the two ends and optionally in which a locking clamp is provided between the two ends.

5. A flue pipe substantially as herein described with reference to, and as shown in, the accompanying drawings.