Description
A. BLADDER TANK FOAM PROPORTIONING SYSTEMAPPLICATION
The Bladder Tank Foam Proportioning System utilises water pressure to inject foam concentrate into water supply and automatically proportions foam concentrate over wide range of flow and pressure, with very low pressure drop. This system does not require a foam concentrate supply pump. SPECIFICATION The Bladder Tank Foam Proportioning Systems are available with vertical and horizontal ladder tanks. The carbon steel tanks are designed and constructed in accordance with ASME Code Section Vlll Div.1 for unfired pressure vessels.
The maximum working pressure is 12 bar (175 psi). The vertical tank assembly is supported by legs welded to tank with provision for anchoring. The horizontal tanks are supported by two saddles welded to the tank and drilled for anchoring. Tank is provided with lifting lugs. The system is supplied with pressure vessel, bladder, fill and drain valve for water and foam concentrate, ratio controller and vent valve. Note: The above images are for representative purpose, actual product may vary depending on the required accessories & specifications. JULY, 2022 PAGE 2 OF 12 HD 191 HD FIRE PROTECT PVT. LTD. Ladder and sight gauge assembly are supplied as optional items on request. All valves are labeled showing normal working position and function. All tanks are oversized for allowing thermal expansion of the foam concentrate, if any. PRINCIPLE OF OPERATION The instructions for filling are provided with the equipment. Once the main water flow is established and water inlet and foam outlet valves are opened, the water enters the area between vessel wall and
bladder, applying pressure to the bladder. The foam concentrate is forced out of the bladder through the foam concentrate outlet pipe and into the ratio controller through metering orifice. The concentrate pressure and water inlet pressure at ratio controller will be same, as the main water supply pressure is utilised to expel the foam from the bladder. The water flowing through the ratio controller jet creates a low pressure area for foam concentrate. This injects the concentrate in to the ratio controller through an accurate sized orifice proportioned to water venturi. This ensures correct proportioning over a wide range of flow condition. The bladder tank proportioning system operates on same principle as that of a balance pressure proportioning system. In bladder system, the bladder is used as diaphragm to separate the water and foam concentrate within the tank. The foam concentrate is injected into the ratio controller utilising water pressure. The system is also supplied with foam concentrate control valve as an optional item. The valve allows concentrate flow only when minimum of 2.1 kg/ sq.cm water pressure is established in the system. For pressure drop and flow characteristics refer
catalogue of ratio controller. HD FIRE Bladder tanks and proportioners are UL Listed and FM Approved with various HD foam oncentrates,
refer individual listing and approval data. “U’ stamp (The American Society of Mechanical Engineers- ASME) code stamp. This ASME certification is optional. Bladder tanks 900 Liters and larger are CE marked on conformance with the European Pressure Equipment Directives. CE marking is optional. SELECTION OF HORIZONTAL/ VERTICAL BLADDER TANKS Advantages of Horizontal bladder tanks
(i) Better stability than vertical tank in earthquake prone area (ii) Easier to refill than vertical tanks (iii) Easy to transport, store and install
(iv) Large Capacity Advantages of Vertical bladder tanks (i) Require less floor space than horizontal tanks INSTALLATION, INSPECTION AND
MAINTENANCE An installation, inspection and maintenance manual is packed with each unit. The manual provides detail schematic, initial procedure, inspection and maintenance procedures. The instruction manual must be read carefully and followed during installation
and commissioning of the system. After few initial successful tests an authorised person must be trained to perform inspection and
testing of the system. It is recommended to carry out physical inspection of the system regularly, the inspector should verify that no damages have taken place to any component and all the valves are in their proper position as per the system requirement. The
system should be fully tested at least once in a year and in accordance with applicable NFPA code or in accordance to the guidelines of the organisation having local jurisdiction. Do not turn off the system or any valve to repair or test the system, without placing a roving Fire Patrol in the area covered by the system. The patrol should continue until the system is put back in service. Also inform the local security personnel and the control room so that a false alarm is not signalled. CAUTION 1) Do not weld on the tank as it may damage the
bladder fitted inside the tank. 2) Release pressure before an inspection and maintenance of the system. 3) Sight gauge is not pressure tight, so before taking concentrate level reading, tank pressure must be released. 4) The bladder tank is to be installed under a shed
to avoid direct sunlight on the equipment. 5) While designing a foam system, step shall be taken to allow for removal of the internal centre tube(s). The centre tubes are full length and/or height of the bladder tank. 6) ASME Code may require over pressure protection
before pressurising the system. HD FIRE does not supply an over pressure relief valve with the tanks. It shall be the owner’s responsibility
to provide over pressure protection for the tank in accordance to ASME Code. 7) Foam concentrate filling procedure must be followed. Incorrect filling procedure may damage the bladder. HD product have limited warranty and incorrect fill procedure will void the warranty.
JULY, 2022 PAGE 3 OF 12 HD 191 HD FIRE PROTECT PVT. LTD. NOTE 1) The foam concentrate is to be filled in the bladder very carefully to avoid rupture of bladder. The filling guidelines provided with the equipment must be strictly adhered. 2) Air supply with regulator (0 to 1.0 kg/sq.cm) required during filling procedure, to be arranged by installer / user. 3) Water supply at 0-1.5 kg/sq.cm required for tank filling during commissioning, to be arranged by installer / user. 4) Concentrate fill pump is to be arranged by installer / user. 5) A minimum length of 5 (five) times the pipe diameter of unobstructed straight pipeline should be provided at the inlet and outlet of the ratio controller, where pipe diameter is the nominal size of the ratio controller. 6) FM Approval of the Bladder tank is applicable as per FM Approved Low Expansion System, where FM Approved Foam Concentrate, Bladder tank, Ratio Controller/Foam Proportioner, Foam
Discharge Devices/ Foam-Water Sprinklers are installed in the system. 7) Foam Concentrate Control Valve is requirement for FM Approval and is not permited by UL. Hence Tanks will be either UL Listed or FM Approved. 8) Multiple Ratio Controllers cannot be used if it is UL Listed Bladder tank. 9) FM Approved Bladder tank can have maximum of two Ratio Controllers, two installed on different sides.
10) Each tank is designed & tested for specific type of foam concentrate, hence specify in order the concentrate type to be used.
11) The systm is to be designed in accordance with latest standard of NFPA11, standard for Low, Medium and High Expansion Foam.
OPTIONAL SUPPLY • Sight gauge with shut off and drain valve (glass or polycarbonate material)
• Ladder
• Pressure Gauges
• Concentrate control valve
• Filling kit with foam concentrate filling pump
• Stainless steel pipe for water supply side
• Stainless steel pipe & valve standard supply
SS304/CF8. Optional is SS316/CF8M or SS316L/CF3M
• Painting as per specific requirement
• Seismic designed tanks
• Custom design for higher rating, material and
dimension
• Internal surface is epoxy painted as standard
supply, or any other paint as per customer
requirement
• Ratio controller material Bronze, Stainless steel
CF8M
• Relief valve is not included in standard supply it
is optional as per specific customer requirement
• Tank design as per specific corrosion allowance.
RELIEF VALVE (OPTIONAL SUPPLY)
(i) Thermal Relief valve
(ii) Full flow, as per ASME
(iii) Full flow, ASME “U” Stamped
LISTING & APPROVAL
1) Bladder tank proportioning system is UL Listed or FM Approved as pre-piped system.
2) Listing and Approval is valid only when used in the manner as outlined in the applicable Listing and Approval.
3) Foam Concentrate Control Valve is standard supply with FM Approved Bladder tank.
4) CE marking is optional. 5) ASME “U“ stamp is optional. SHIPPING DETAILS
i) All the tank openings will be plugged for shipping.
ii) All pre-piped pipes, valves, pressure gauges, sight gauge etc will be packed separately for shipping. iii) Tank will be mounted on pallet with crate all over as standard packing system of HD FIRE. For any custom packing requirement contact HD Sales
