Patent Publication Number: US-6041820-A

Title: Service and heating water combined expansion tank

Description:
FIELD OF THE INVENTION 
     The invention relates to an expansion tank for receiving volume changes caused by temperature fluctuations in service and heating water systems, comprising a vessel divided by means of a diaphragm into a pressurized gas space and a water space, the water space having ports for connection to a water system. 
     BACKGROUND OF THE INVENTION 
     In both service water systems and heating water systems, temperature variations may cause the liquid medium--usually water--to undergo volume fluctuations. Such temperature dependent volume fluctuations are compensated for by expansion tanks of the type known by DE 4013897 C2, for example. These expansion tanks are placed under a predetermined pressure to urge incoming water back into the respective systems as temperatures change. 
     Conventional service water systems are pressurized to approximately 4 bar, whereas heating systems conventionally operate at a pressure of 1.5 to 3 bar. The expansion tanks are necessary for technical reasons, but occupy a certain amount of space and cause additional material expenditures. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an expansion tank of the type specified above which reduces the space requirements for the water systems involved, as well as the material expenditures incurred. 
     The above object is achieved by a service water space or compartment and a heating water space or compartment integrated in a common tank. As a further development, the service water space is provided in a service water expansion vessel and the heating water space in a heating water expansion vessel, the service water expansion vessel being separated from the heating water expansion vessel by a partition. 
     These measures result in an expansion tank suited to receive expansion water from two different water systems. The amounts of water received at any one time may differ, as can the pressures in the respective systems. This renders one of the vessels unnecessary since the remaining one will serve two water systems. As a result, installation labour and expenditures will be reduced substantially. 
    
    
     Additional advantageous measures are described in the dependent claims. The invention is shown in the attached drawing and is described in greater detail hereinafter. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1, is a schematic drawing showing the expansion tank of the present invention. 
     REFERENCE NUMERALS 
     
         ______________________________________                                    
10             Expansion tank                                             
  11 Top portion of the tank                                              
  11a Bottom portion of the tank                                          
  12 Tank port opening                                                    
  12a opening edge                                                        
  13 Lid                                                                  
  13a Lid threaded fastener                                               
  14 Service water port                                                   
  15 Service water expansion vessel                                       
  16 Diaphragm                                                            
  16a Diaphragm bead                                                      
  17, 17a Supply valve                                                    
  18 Service water compartment                                            
  19 Pressurized gas compartment                                          
  20 Partition                                                            
  21 Heating water expansion vessel                                       
  22 Diaphragm                                                            
  22a Diaphragm bead                                                      
  23 Heating water compartment                                            
  24 Pressurized gas compartment                                          
  25 Vessel dividing plane                                                
  26 Clamping ring                                                        
  27 Heating water port                                                   
  28 Service water system                                                 
  29 Heating system                                                       
  30 Foot                                                                 
______________________________________                                    
 
    
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown schematically in the single drawing figure, a partition 20 divides expansion tank 10 to contain a service water vessel 15 and a heating water vessel 21. Expansion tank 10 preferably consists of sheet steel and has partition 20--also preferably of sheet steel--welded in place therein. Suitable plastics material may be used as well and joined by adhesive bonding. 
     Expansion tank 10 comprises a vessel top portion 11 and a vessel bottom portion 11a, which are separated at a division 25. Top portion 11 has therethrough an opening 12 designed to form a manhole; it may serve as an inspection opening as well. Opening 12 is adapted to be closed by means of a lid 13. Lid 13 is an embossed member and releasably secured around the edge 12a of opening 12 by means of threaded fasteners 13a. 
     Opening 12 has a diaphragm 16 inserted therein. Diaphragm 16 preferably is an inflatable bubble type diaphragm and has a diaphragm bead 16a. Bead 16a engages edge 12a of opening 12 where it serves as a seal for lid 13 also. 
     Diaphragm 16 divides service water vessel 15 into a service water compartment 18 and a pressurized gas compartment 19. Compartment 19 can be pressurized through supply valve 17 with a gas to a pressure level of approximately 10 bar. Service water vessel 15 communicates through a service water port 14 with a service water system (not shown in detail). Service water compartment 19 is defined by diaphragm 16 so that the water will not contact the walls of top portion 11. 
     A second diaphragm--preferably a pot type diaphragm in the embodiment here described--is inserted at division 25 between top portion 11 and bottom portion 11a of the vessel. Diaphragm 22 has a bead 22a which also serves as a seal between top portion 11 and bottom portion 11a. 
     Top portion 11 and bottom portion 11a are joined by means of a clamping ring 26. Clamping ring 26 is arranged to be releasable by using closure means not shown in greater detail herein. 
     Diaphragm 22 divides heating water expansion vessel 21 in bottom portion 11a into a pressurized gas compartment 24 and a heating water compartment 23. Compartment 24 may be filled with a pressurized gas through a second supply valve 17a. Heating water compartment 23 communicates through a heating water port 27 with a heating system 29 (not shown in detail). The heating water from heating system 29 contacts the inner walls of bottom portion 11a of the vessel, while the pressurized gas is in the pressurized gas compartment 24 partly defined by diaphragm 22. 
     Expansion vessel 10 may be set up on feet 30 at a location suited and intended therefor (not shown in detail) inside a building.