Viking VFT - Section 3 - Equipment Description; Bladder Tank Description and Principle of Operation; Bladder Tank Design Data

BLADDER TANK MODEL VFT & FT
INSTALLATION, OPERATION AND
MAINTENANCE MANUAL
(
foam concentrate inside the bladder
)
TECHNICAL
MANUAL
F_032216 16.1 | TM1.3.1.1/14032016/en
The Viking Corporation, 210 N Industrial Park Drive, Hastings MI 49058
Telephone: 269-945-9501 Technical Services: 877-384-5464 Fax: 269-818-1680 Email: techsvcs@vikingcorp.com
VISIT THE VIKING WEBSITE FOR THE LATEST EDITION OF THIS TECHNICAL MANUAL
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SECTION 3 – EQUIPMENT DESCRIPTION
3.1 Bladder tank description and principle of operation
The Viking bladder tank stores foam concentrate inside the bladder. When used in conjunction with the Viking Ratio Controller it
proportions the foam concentrate accurately into the water stream. The outer shell of the bladder tank is pressurized by the system
water supply then during extinguishing system operation; foam concentrate is squeezed out to the ratio controller. Simultaneously,
as water ows through the venturi area of the ratio controller, a metered pressure drop also draws foam concentrate into the system
water creating a foam solution mixed to the appropriate ratios. This solution then ows through the system pipework and out of the
open sprinklers, nozzles or other discharge devices.
The pressure tank is manufactured either according to ASME Sec. VIII Div. 1 or EN13445 design codes. Please check the
equipment nameplate for the code relevant to your bladder tank.
3.2 Bladder tank design data
As a pressure vessel, the bladder tank supplied by Viking can be manufactured according to different design codes - see previous
section - as indicated in the identication nameplate placed on the tank’s shell.
Depending on the requirements of the project, the tank design can additionally be validated as compliant with the European
Pressure Equipment Directive 97/23/EC. This requirement shall be specied at the Ordering stage. When the Viking bladder tank is
manufactured according to the standard EN-13445 “Unred pressure vessels”, this is also compliant to the Directive 97/23/EC.
The following design data applies to standard bladder tanks of volume ranging from 1,000 to 20,000 liters:
When validated as compliant to Directive 97/23/EC, all the above bladder tanks are CE marked.
Table 3.2.1: Design data
Internal volume See nameplate (from 1,000 litres to 20,000 litres)
Design pressure Ps 12.1 barg (175 psig) or 16 barg (232 psig)
Minimum/maximum metal design temperature Ts -10 °C, +50 °C
Hydraulic test pressure ASME VIII Div.1:
ASME VIII Div.1 + PED:
EN 13445:
1.3 x Ps
1.43 x Ps
1.43 x Ps (c(*)=0,85) or
2.20 x Ps (c(*)=0,70)
Corrosion thickness 0,0 mm
Fluid / physical state Water-foam concentrate / Liquids
Fluid group (Art. 9 of 97/23/EC, if applicable) Gr. 2
Category (Annex II of 97/23/EC, if applicable) I
Evaluation form (Annex III of 97/23/EC, if applicable) A
(*) C is dened as Welding Joint Efciency coefcient as reected by the design calculation