Water Expansion Tank Pressure Pre-Charged with a 38 Psi Air Charge

Expansion Vessels - Why?

In practice water cannot be compressed and therefore any increase in water volume must be accommodated in an expansion vessel designed and sized for that purpose. Naturally, as water heats up, it expands. This expanded water has to go somewhere. In an open type system the open expansion tank situated at the highest point of the system would accommodate this extra volume. A closed type system does not have an open fixture such as described above. Hence, a correctly sized Dezhi/Aqua Leader expansion vessel is necessary. When properly sized, the Dezhi/Aqua Leader Expansion Vessel will accommodate the expansion of the fluid during the heating or cooling cycle without allowing the system to exceed the pressure limits of any of the components in the system.

Configuration and Features

Dezhi/Aqua Leader  Expansion Vessels incorporate a diaphragm/bladder arrangement which provides a flexible barrier between the system fluid and the precharged air in the vessel. As the system water expands, the bladder also expands pushing against the precharged air cushion. This is how the expansion is accommodated in a closed-loop system.

Standard construction is carbon cold pressed steel with natural rubber or EPDM membranes.

Temperature limits are 10oC to 99oC.

Working pressures vary from 3 Bar to 35 Bar depending upon which vessel is selected. Higher pressure ratings of 45 and 50 Bar are available if required.

Other Features

• Replaceable bladder

• Threaded connections - stainless.

• Pre-set pressure 400KPa - variable.

• Wall mount bracket available for 8-36 litres.

• Also available in stainless steel.

• Relief valve supplied loose to suit system pressure - please specify.

Sizing for Expansion Vessels

In order to select a suitably sized expansion vessel, the following information is required:

• Total system water volume in litres.

• Temperature of water when system is filled (in oC) and average maximum operating temperature (in oC).

• Minimum operating pressure in kPa and maximum operating pressure (10% below relief valve, in kPa).

• Which level of the building it will be installed and number of levels there are above it?

Suggested Specification 

Expansion Vessels shall be the closed type similar to Dezhi/Aqua Leader  (available from Taizhou Tianyang Electrical Co., Ltd ) or approved equal and suitably sized to suit the system temperature and pressures likely to be encountered. Vessels construction to be fully welded and sealed steel construction, complete with integral EPDM rubber liner to maintain the water within the system without exposure to air or contamination. Each Vessel to be supplied with a suitably safety relief valve vessel must have a replaceable bladder.

Taizhou Tianyang Electrical Co., Ltd reserves the right to make changes without notification.


Introduction

Dezhi expansion vessels are suitable for use in central heating and cooling installations.

Nitrogen, a dry inert gas used in the Dezhi/Aqua Leader range of expansion vessels, improves the vessel's life span by reducing corrosion inside the vessel, and prevents loss of pre-charge pressure. Nitrogen permeates through rubber slower that oxygen and is far less reactive to both steel and aluminium creating fewer debris inside the vessel. Nitrogen does not degrade rubber prolonging the membrane life.

Oxygen in compressed air permeates through the membrane, thus reducing the pre-charge pressure over time. During normal operation, oxygen oxides the membrance in the vessel, causing under inflation pressure and will not corrode the inside of the vessel.

It's recognised in the industry that oxidative ageing is one of the primary causes of decreased vessel life. Tests have shown that if vessels are inflated with Nitrogen, there is a significant reduction in failure and increased vessel life.

For use under high pressure. Top-quality high strength steel, with a gleaming red (RAL 3002) epoxy powder coating - perfect protection and finish. Clamp ring of heavy-duty thermally-galvanised steel. Our flexible EPDM Bladder with rolling action are suitable for use with glycol based anti-freeze addition up to 50%. Exact details are available on request. The nitrogen airvalve is sunk and cannot be damaged due to the cap and extra protective plastic beige coverplate. Uncoated threaded system connection, ensuring problem free connecting.

Specifications

• Max. working pressure: 10 bar(g)
• Max. temperature at (heating) outlet: 99 °C.
• Max. temperature diaphragm: 99 °C (DIN4807/3).
• Max. supply temperature (boiler): 90 °C.
• Min. working temperature: -10 °C
• In accordance with Pressure Equipment Directive 97/23/EG.

The main elements of the membrane tank are a metal case of high-quality deep-drawn steel and an elastic membrane made of Butyl Rubber Membrane separating the tank into two chambers - an air (cavity between the metal case and a membrane) and a water one (the internal cavity of the membrane). The air chamber is constantly under a pre-set air pressure. The service life of diaphragm tanks is at least 10 years of continuous operation. The durability of the membrane - at least 100,000 cycles. Dupont (France) materials are used as paint. 

Features of the design - the location of the top flange (TOP tanks) provide ease of installation / disassembly of the equipment, virtually eliminates the possibility of air plugs in the water cavity of the membrane, the minimum time required to replace the membrane; small overall dimensions.





Technical Parameter 





How a Expansion Tank Works







Company profile 

Taizhou Tianyang Electrical co., LTD. Is located in Shangma industrial Zone, Shitang Town, WenlingCity, Zhejiang rovince, covering an area of 15, 000 square meters. Our Company has over 30 years experience in mold design and exploition. "DEZHI"and "AQUALEADER" are our proprietary brand of our company. We have produced pressure tank for more than 20 years. Available volumes range from 0.15 to 1500 liters. and working pressure from 4 bar to 25bar. Our products are applied to pump systems. Our products are exported to numerous overseas clients. We can custom design and manufacture products according to client-supplied requirements. 
We adhere to the business philosphy"Credibility, Quality and service", our scientific management is based on the domestic market, but facing to the world. Warmly welcome customers both domestic and from abroad. We sincerely hope to cooperate and develop together to create a better future. 
Taizhou Tianyang Electrical Co., Ltd. Is always your most loyal partner.  

I would like to take this opportunity to introduce our company to you. I am contacting you on behalf of  Taizhou Tianyang Electrical Co., LTD.

We are the factory from China for making Pressure Tanks for Fire Protection, Residential Water and Irrigation, Sport Turf and Landscape Irrigation, Agriculture and Horticulture Irrigation, Water Filtration, Treatment & Recycle, Solar and Stock Water System, Rain Water Harvesting, Pump Systems. Based on ISO quality management system, we have obtained CE, KC, ISO 9001, ISO14001, OHSAS 18001, SGS, Water Mark, and Wras Certificates for our company & our Pressure Tanks. Welcome to visit  Taizhou Tianyang Electrical Co., LTD when it is more convenient for you. 



Basic Introduction 

The pressure vessel is designed to provide a storage facility and pressure reservoir for water at temperatures up to 99ºC. Common uses are in water booster sets, heating pressurisation and fill sets. The vessel incorporates a replaceable Butyl diaphragm mounted in a mild steel shell. This method of construction eliminates any contact between the stored water and the steel shell of the vessel, and is therefore suitable for use with potable water. All units up to and including 25 litre sizes are suitable for a working pressure of 8 bar, larger vessels 10 bar, (except 1000LV)

For Water-Dezhi Series 

Interchangeable membrane pressure tanks.

Membranes suitable for drinking water and can be installed to any type of pump.

WRas approved and built to 97/23/EC

Technical Parameter   Regarding Installtion 

The vessel is supplied pre-charged with air, but this pressure may require adjustment to suit the site conditions. This adjustment must be made with the vessel isolated from the system, and before filling with water. Air may be vented from, or pumped into, a patent valve which will be found under a black plastic screw-off cover on the shell (sizes up to and including 500 litre) or on a side mounted flange (750 and larger). It will be noted that vessels of 60 litre capacity or larger are manufactured with connections at either end of the vessel shell. The vessel should be mounted so that the system connection is made at the lowest possible point, to facilitate on-site maintenance. The other connection may be fitted either with a air bleed valve, or alternatively with a blanking plug. All pressure vessels should be installed with an isolating valve and drain cock.

Periodic Maintenance

The only maintenance required on this equipment is a periodic check on the air cushion pressure. It is necessary to isolate the vessel from the system, and to drain all water from the tank before making this measurement with a standard tyre pressure gauge from the  valve.

Maintaince free models are also available,Please refer to customized Model Or Contact Mr.Tom Lee (Export Models Only)




FAQ Details:  

1. Q: What is your MOQ of this item?
  A: We are a factory, have stock. 1PCS is ok!

  2. Q: What is the delivery time?
  A: 7-25 days after receiving orginal L/C or deposit by TT.

  3. Q: Is it all right to make customer's own brand name?
  A: Yes we supply OEM service. Please send us a authorization doc.

  4. Q: Where is your Loading Port?
  A: Ningbo, Zhejiang, China.

  5. Q: What are your payment terms? For Bulk Quantity Purchase
 A: 30% deposit and balance T/T against copy of Bill of Lading or L/C at sight.
  For Samll amount Trial Order, Please arrange the full payment

  6. Q: What is your company's available production capacity?
  A: 50000~60000 pieces of Pressure Tank per month. 

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