Rainwater Tanks

Pillow type rainwater tanks are designed to collect and store the rainwater. For many different reasons, the users want to collect the rainwater for irrigation, fire-fighting, municipal water, or even drinking water. Rainwater storage tanks provide one great collection and storing system solution that are cost-effective and well-work for you. Rainwater collection tanks are low profile while filled. So it can be put in most of the places.

Normally, the fabric is non-potable grade. If you will use the rainwater for drinking water purposes, we could also make these pillow rainwater bladders with NSF certificated material.

rainwater pillow tank
rainwater storage tank

Rainwater Storage Tanks Structure

Please refer below general drawing for the small, middle and large rain water storage tanks.

rainwater pillow tank structure

  • Inlet Fittings:  The standard filling fitting is 2”, 3” and 4” high quality PP flange with cam-lock with one safety cap (refer below picture). The other material filling port and camlock are available upon request. We can do aluminum or stainless steel flange and cam-lock, with stainless steel or brass ball valves.

  • Outlet Fittings:  The standard filling fitting is 2”, 3” and 4” high quality PP flange with cam-lock with one safety cap (refer below picture). The other material filling port and camlock are available upon request. We can do aluminum or stainless steel flange and cam-lock, with stainless steel or brass ball valves.

  • Optional: Groundsheet can protect your rainwater tanks. It will be supplied upon request.

rainwater tank accessories

Fill/Discharge Valve(2″ or 3″)

Drain Valve(2″ or 3″)

Air Bleed

Rainwater Bladders Specifications

DOOWIN rainwater storage pillow tanks are from 200L to 800,000L. Below you will find our standard specification of rain storage tank. Customized size and shape are available upon request. If you have any special request, please contact us now.

rainwater tank bladder specifications

Advantages and Features

DOOWIN rainwater pillow tanks are produced by HF welding technology for better performance. Don’t use glue or hot-air. There are features and advantages to ensure rainwater storage tanks to be the best container for collection and storage of rainwater.

  • Low profile when filled
  • Flat when empty
  • UV resistant, oil resistant
  • Top notch UV resistance
  • Excellent abrasion properties
  • Light weight, High strength
  • Easy to storage and shipment
  • Easy to setup and operate
  • Wide range of use
  • Wide range capacities up to 800 m3
  • Customized shape and size available
  • Various filling/discharge fittings
  • Can be used for potable drinking water tanks
  • Fabric meet NSF 61 requirements
rainwater pillow tank advantages
HF welding technology

Innovative HF Welding Technology

DOOWIN rainwater storage tanks use HF welding technology. The HF welding seams have better tensile strength than the hot-air welding seams. It has more stable performance, not easy to separate for long term storage.

hot air welding technology

Traditional Hot-Air Welding Technology

We abandon the traditional hot-air welding technology. The hot-air welding seams are not persistent. The seam is easy to seperate. Some inferior bladders prefer this welding.

Rainwater Tanks Material

Normally, the fabric used to construct the rain storage pillow tanks are non-potable grade. If you will be using the rainwater for drinking water purposes, we also can make these pillow rainwater tanks with NSF certificated material.

PVC Coating Fabric Material: This material is the same as the Non-Potable Water Bladders Material. DOOWIN use the top grade fabric for these non-potable water bladders.

Our rainwater tanks are made of extremely robust flexible fabric material. These fabrics have high-strength polyester base fabric and special inner coating. It has super high UV resistant or oil resistant. So it is not easy to crack after long time use.

Potable Water Tanks Material:  This material is the same with our potable water tank’s material. We have to ensure the quality of the drinking water that stored in our pillow tanks cannot be affected by contact with other material.

DOOWIN use the top grade fabric for the drinking water storage tank made in Germany. These fabric material got the certificates with the American NSF/ANSI 61, KTW, ACS or FDA standards. So it ensures that our portable water tank does not pose any risk of contamination to drinking water.

SGS logoNSF certificate

Rainwater Tanks Applications

We can make the collapsible rain water collection tanks for below application but not limited to. In one word, if you want to store rain water, choose DOOWIN rainwater pillow bladders.

  • Cistern
  • Collection rainwater
  • Rainwater storage
  • Garden irrigation
  • Storage rainwater for re-use
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