Tested to BS EN 1856-2 and BS EN 1443
Introduction Page 2 Midtherm Flue Systems Limited is an independent British manufacturing company producing a wide range of flue and chimney products, along with associated components and services. Established for over 30 years, Midtherm products are installed worldwide including Poland, Oman, Libya, Hong Kong, China and the USA. Quality Assurance All products are controlled by a Quality Assurance System certified to ISO 9001:2000, products have been tested to EN 1856-2 at BSRIA, report number 52022/1. Product Specification Midflex 316L Midtherm Midflex 316L is a twin wall flexible liner made from 316L grade stainless steel and produced to the highest standards. The Midflex 316L has good resistance to pitting and crevice corrosion. Where lower a temperature/slumbering operation may be encountered our 904L product should be used as this grade of stainless steel provides better corrosion resistance to condensation. Midflex 904L Midtherm Midflex 904L a twin wall flexible liner made from 904L grade stainless steel (a high performance austenitic stainless steel) with high levels of chrome, nickel, molydbenum and copper which provide it with exceptional corrosion resistance. The Midflex 904L is extremely resistant to pitting and crevice corrosion and has very good resistance to stress corrosion cracking. An extensive range of fittings have been designed for use with both Midflex 316L and 904L products ensuring that installations have the best equipment available to suit individual installation requirements. SPECIFICATION Midflex 316L Product Midflex 904L Materials: Stainless Steel 316L inner and outer 0.12mm thick Stainless Steel 904L inner and outer 0.12mm thick Construction: Designations: Installation Designation: Performance: Crisis Operation: Fuels: Life Expectancy and Warranty: Inner Wall - Smooth bore construction giving extremely low resistance to flue gas flow Outer Wall - Convoluted outer profile with a crimped and locked seam. The two walls are seamed together throughout the length of the product to ensure its stability and integrity. Solid fuel applications: BS EN 1856-2 T450 N1 D Vm50012 G(0) Gas and oil applications: BS EN 1856-2 T250 P1 W Vm50012 O(0) Solid fuel applications: EN 1443 - T450 N1 D3 G(0) Gas and oil applications: EN 1443 - T250 P1 W2 O(0) Solid fuel applications: BS EN 1856-2 T450 N1 D Vm70012 G(0) Gas and oil applications: BS EN 1856-2 T250 P1 W Vm70012 O(0) Solid fuel applications: EN 1443 - T450 N1 D3 G(0) Gas and oil applications: EN 1443 - T250 P1 W2 O(0) Normal operating temperature up to 450 C for solid fuel applications and up to 250 C for gas and oil applications. The liner will withstand thermal shock at 1000 C for a short duration in emergencies. However, such conditions will have a detrimental effect on the product life. In the event of a chimney fire the liner should be inspected by a competent person before re-use. Records should be kept of such inspections. Coal, coke, anthracite, cured dry logs, cured dry peat, and all normal fuel oils, gas. Details of suitable fuels can be obtained from HETAS. Under normal operation with correctly set and operated appliances using fuels of recognised quality with low sulphur content. The product is offered with a 10 year warranty cover. If slumbering operation is likely to occur then our 904L product should be used. The product is offered with a 25 year warranty cover. In order to register for warranty cover please complete a registration form (replacement of product only), subject to warranty conditions. The product will not be guaranteed if refuse or plastic is burnt, or if the appliance is in a situation where substances containing chlorine or fluorine are used. Installation: Maintenance: Product must be installed and commissioned by competent professional installers. The chimney must be swept at least once a year by a professional sweep using non-metallic brushes. Chemical cleaners must not be used. Available Dimensions: 100mm (4 ), 125mm (5 ), 155mm (6 ), 180mm (7 ), and 200mm (8 ). 100mm (4 ), 125mm (5 ), 155mm (6 ), 180mm (7 ), and 200mm (8 ).
Page 3 Dimensions Dimensions 4 5 6 7 8 (100mm) (125mm) (155mm) (180mm) (200mm) Code 04 05 06 07 08 Internal Diameter (mm) 100 125 150 180 200 External Diameter (mm) 106 131 156 186 206 Coil Length (M) 40 40 40 30 30 Available in Midflex 316L * Available in Midflex 904L * * Special order only. Approx Product Weights Product Weight Per M (kg) 316 904 5 1.3 1.3 6 1.4 1.3 7 1.5 1.5 8 1.55 1.55 General Notes 1. An increase in fuel consumption, smoke in the building, evidence of sooting, difficulty in lighting, and staining around the appliance casing generally indicates a problem either with the appliance or that a blockage in the system may have occurred. 2. Do not use chemical cleaners on the flue. 3. Do not block or obstruct flue outlets or chimneys. 4. Do not cover appliance. 5. Running appliances on constant low heat produces an increased level of condensation and may shorten the life of the product. 6. Burning low grade fuels with high sulphur content can shorten the life of the product. 7. Any personnel installing or carrying out work or maintenance on appliances and flue must be suitably qualified and competent to do so. 8. After installation the chimney should be inspected to determine the frequency of sweeping required. 9. When carrying out smoke tests/spillage tests, consideration should be given to fans, draughts and combinations of the two which may affect the results of the test. Installation Guidelines: For detailed installation guidelines please to refer to the following documents: Twin wall flexible flue liner installation instructions Twin wall flexible flue liner warranty information HT Plus brochure and installation instructions SW 316 brochure and installation instructions Vitrelux brochure and installation instructions HETAS - Heating Equipment Testing and Approval Scheme NACS - National Association of Chimney Sweeps Building Regulations Planning Office BS 5440 - BS 5854 - BS EN 15287-1:2007(E) Appliance Manufacturer s Operating and Maintenance Instructions Termination Heights Up to 160kW - Building Regulations Document J Up to 150kW - BS 6644 Over 150kW - Clean Air Act Midtherm Midflex liner internal section with representation of the fumes direction and condensate flow. Installation The product s flexibility enables it to be handled and installed with minimum curvature radii (see Figure 1) compared to competitor products while still avoiding any deformation of the inner wall. Versatility, practical assembly procedure and rapid installation together with the technical characteristics of the product (extremely low fume resistance, rapid temperature stabilisation) ensures the flex systems meets the requirements of most operations. When un-packing the product, uncoil the flex from the outside of the coil, removing the packaging to do so. This is necessary to avoid exceeding the minimum curvature radii. Uncoiling from the inside of the coil will damage the flex and void your warranty. Please see the packaging instructions for futher details. When installing the liner, attention must be paid to the arrows marked on the liner, which indicates the fume flow direction. Figure 1 100 180 125 235 155 260 180 280 200 320
Lengths and Packs Page 4 Stocks Midflex 904L Coil Code 70 Midflex 316L Coil Code 60 The liners are available in diameters 100mm - 155mm in 40 meter coils and 175mm - 200mm in 30 meter coils. 100mm are available on special order only. Midflex Coils Code 35 Code 100mm 125mm 155mm 180mm 200mm 04 05 06 07 08 Midflex 904L per Metre 70 * Midflex 316L per Metre 60 * Standard Coil Length 40m 40m 40m 30m 30m * Special order only. Midflex Packs Code 35a Midflex 904L Midflex 316L Length (m) 6 7 8 9 10 11 12 6 7 8 9 10 11 12 Code 71 72 73 74 75 76 77 61 62 63 64 65 66 67 125mm 05 Diameter 155mm 06 180mm 07 200mm 08 For full prices on our flexible products please see our current price lists (copy available on request). Ancillary Components Single to Twin Adaptor Item Code 10 Single to Twin Adaptor with Bolts Item Code 10a Designed to connect Midtherm Flex to Midtherm SW316 single wall flue or Midtherm Vitrelux. Available with or without retaining bolts. 110 Single to Twin Adaptor Longtail Item Code 10b Single to Twin Adaptor Longtail with Bolts Item Code 10c Designed to connect Midtherm Flex to Midtherm SW316 single wall flue or Midtherm Vitrelux. The longtail allows the flue to be adjusted if required. 245 Available with or without retaining bolts.
Ancillary Components Page 5 Single to Twin Increaser Item Code 11 Single to Twin Increaser with Bolts Item Code 11a Designed to connect Midtherm Flex to Midtherm SW316 single wall flue or Midtherm Vitrelux where an increase in flue diameter is required. 215 Available with or without retaining bolts. 285 Single to Twin Increaser Longtail Item Code 11b Single to Twin Increaser Longtail with Bolts Item Code 11c Designed to connect Midtherm Flex to Midtherm SW316 single wall flue or Midtherm Vitrelux where an increase in flue diameter is required. The longtail allows the flue to be adjusted if required. Available with or without retaining bolts. Clamp Item Code 12 Used to clamp the Flex at the top or bottom of a flue run. Plate Item Code 13 Used to close the top or bottom chimney opening. 400 (SQ) Flue Support Bracket Item Code 14 Used to clamp the Flex at the top or bottom of a flue run. Protection Sleeve Item Code 15 Used to protect the termination end of the flex. 105 Gather Adaptor Item Code 16 For use at the fire place end of the chimney to allow for a larger collection area. 310 320 (SQ)
Sundry Components Page 6 A Standard Cowl Item Code 18 Designed for use on natural draught systems to reduce back pressure in the flue. Also acts as a rain cap. Diameter Code 05 06 07 08 Bore 125 155 180 200 A 250 300 350 405 B 250 280 290 310 B Nose Cone (Stainless Steel) Item Code 19 Used for testing the chimney cavity prior to installation and also aids with the final installation. Please see installation instructions for more details. Available in all sizes. Standard Clay Pot Adaptor Midtherm Clay Pot Adaptors are designed to install multifuel flexible liner without having to remove the clay pot. Its unique system of clamping the flexible liner to the pot adaptor ensures a positive connection. Made in 316 grade stainless steel. Available in 125mm (5 ), 155mm (6 ), 180mm (7 ) and 200mm (8 ). Also available with mesh at extra cost. See price list 22. 240 Clay Pot Adaptor with Standard Cowl Midtherm Clay Pot Adaptors are designed to install multifuel flexible liner without having to remove the clay pot. Its unique system of clamping the flexible liner to the pot adaptor ensures a positive connection. Made in 316 grade stainless steel. 385 Available in 125mm (5 ), 155mm (6 ), 180mm (7 ) and 200mm (8 ). Also available with mesh at extra cost. See price list 22. Flex Insulation Used for insulating flexible liners in large chimney cavities. Pre-fabricated 1200mm lengths with 30mm thick Rockwool insulation, foil facing and intergrated self adhesive slip. 1200 Available in 125mm (5 ), 155mm (6 ), 180mm (7 ) and 200mm (8 ). Chimney Data Plate Stainless Steel Chimney Data Plate.
Typical Installation Page 7 GENERAL 1. The full length of the liner must be installed within a solid brick chimney 8. Provision for inspec on/sweeping must be made. Inspec on Lengths are cavity. i.e. there must be a fireproof enclosure between the flue liner and available for this purpose. combus ble material. A minimum clearance of 25mm between the 9. For condensing or posi ve pressure applica ons double connectors flexible flue liner and the wall of the chimney must be maintained along should not be used. Care should be taken to ensure that all components the length of the liner. used allow condense to run back to the appliance or tee cap with drain. 2. The flue liner should be installed with a minimum of offsets and the 10. Chimney components shall not be modified. minimum Curvature Radii must be observered. For gas installa ons the 11. Chimneys penetra ng walls shall be sleeved/shielded and distance between bends should not exceed half of the ver cal height of weatherproofed if through external walls. the chimney and the angle should be no greater than 45. For solid fuel or oil fired installa ons the distance between bends should not exceed 12. Single to twin wall adaptors are available, and can be used to convert to 20% of the ver cal height of the chimney and the angle should be no twin wall flue for T450 system chimney (i.e. HT Plus) applica ons or for greater than 30. external use to improve the resistance to corrosion of the product. 3. The flue liner diameter should never be reduced to less than the diameter 13. Where specified, lightning protec on of the chimney shall be installed in specified by the appliance manufacturer, in some cases this may involve accordance with EN 61024-1. an increase in diameter from the appliance spigot. 14. Weatherproofing where chimneys penetrate roofs shall be in accordance 4. Ensure that adequate air is available for combus on. Refer to Building with the installa on instruc ons. Regula ons Document J. 15. A variety of terminals are available for all applica ons. Chimneys in 5. Ensure chimney termina on has adequate clearance from the roof of the exposed loca ons can benefit from An Down Draught, H or Roto Cowls. building. Do not allow products of combus on to be discharged where Top Stubs are recommended for use on solid fuel appliances, drain points they can enter an opening window or ven la on inlet. can be used to overcome the problem of rain entering the open terminal. The use of mesh cowls should be avoided on solid fuel appliances as they 6. The flue liner must not be fi ed directly onto a solid fuel appliance. A need regular inspec on and cleaning to avoid soo ng up. minimum length of 600mm of connec ng flue pipe must be installed from the appliance to the flue liner. 16. The finished installa on shall have a chimney plate as detailed in the HT Plus Installa on Instruc ons. The correct installa on designa ons are 7. The flue liner should be adequately supported with no weight being detailed in the Specifica on Table on page 2 of this brochure. supported by the appliance itself. A full range of support brackets are available. We recommend no more than 12m ver cal rise between load 17. On comple on of the installa on it should be commissioned in line with bearing support brackets. Addi onal support brackets should be installed the requirements of BS EN 15287 or BS 5440 as appropriate including a to support non-ver cal sec ons. smoke test (see also the Opera ng and Maintenance Instruc ons). If there are any leaks, or any significant spillage, the fault must be rec fied Connecting Flue Pipe Installation before the appliance is used. 18. Provisions must be made for the drainage of condensate where required. Chimney Pot 19. Where posi ve pressure may occur, high temperature caulking compound or silicone sealant (depending on the applica on and temperature) should be used and is available on request. Clamp Closure Plate The above notes are an outline only of some of the aspects of good chimney installa on prac ce. Please refer to the documents listed inside the front cover for further guidance. Midflex 316L Liner Wall Bracket Clamp 1m Vitrelux as connecting flue pipe with clean out door Chimney Closure Plate Stove