Texas Metal Tanks 500 Gallon Galvanized Water Storage Cistern (MPN: TM-MT500G-WS)

Description

The Texas Metal Tanks 500 gallon galvanized steel cistern (TM-MT500G-WS) is a riveted, built-to-order steel water tank made at the Texas Metal Tanks factory in Dripping Springs, Texas, from American-made steel. It measures 48″ in diameter with a 68″ (5'-8") sidewall; the top adds height above the sidewall. Texas Metal Tanks states its tanks are suitable for potable (drinking) water.

The sidewall and bottom are G-90 grade 20 gauge galvanized steel and the top is 22 gauge. After the tank is built, a paint / epoxy lining is applied to the interior as a barrier between the water and the metal. Texas Metal Tanks states the lining is FDA approved for potable water and ANSI / NSF 61 certified, and every tank is tested at the factory to make sure it is watertight. Texas Metal Tanks lists a 20-30 year life span for its galvanized cisterns.

This listing is the Water storage (WS) fittings package: two 1-1/4″ bulkhead fittings, one at the top of the sidewall and one at the bottom, staggered. Tanks are not designed to hold pressure; they are self-venting.

Key Features

• Capacity: 500 gallons
• Size: 48″ diameter x 68″ sidewall height
• Material: G-90 grade 20 gauge galvanized steel; 22 gauge top
• Potable water: Interior paint / epoxy lining, FDA approved, ANSI / NSF 61 certified
• Fittings: Water storage (WS) fittings package - two 1-1/4″ bulkhead fittings, one at the top of the sidewall and one at the bottom, staggered
• Made in the USA: Built to order in Dripping Springs, Texas, from American-made steel

Specifications

• Manufacturer: Texas Metal Tanks
• Part number: TM-MT500G-WS
• Capacity: 500 gallons
• Diameter: 48″ (4')
• Sidewall height: 68″ (5'-8") - the top adds height above the sidewall
• Estimated weight (empty): 210 lb
• Sidewall and bottom: 20 gauge G-90 galvanized steel
• Top: 22 gauge
• Interior: Paint / epoxy lining, FDA approved, ANSI / NSF 61 certified
• Bulkheads: (2) 1-1/4″ polypropylene bulkheads, female NPT, EPDM gasket - one at the top of the sidewall, one at the bottom, staggered
• Pressure: Not designed to hold pressure (self-venting)
• Factory test: Each tank tested for watertightness
• Life span (manufacturer): 20-30 years
• Warranty: 1 year
• Ships From: Texas

Applications

• Rainwater harvesting from a roof or downspout
• Potable (drinking) water storage
• Irrigation and garden water storage
• Well water storage
• Stormwater detention for residential and commercial sites

Frequently Asked Questions

ORDERING AND FITTINGS

What fittings does this tank come with?
This listing is the Water storage (WS) fittings package: two 1-1/4″ bulkhead fittings, one at the top of the sidewall and one at the bottom, staggered. Bulkhead outlets are offered in 3/4″, 1-1/4″ or 2″, PVC inlets and overflows in 2″ (well-fed tanks only), 3″ or 4″, and basket inlets in 12″ or 16″ (an 8″ basket is used on the 140 gallon tank).

How do I choose fitting locations?
Texas Metal Tanks uses a clock diagram. The Texas Metal Tanks logo is at 6:00, the smoothest side of the tank with no seams. Looking at the logo, 3:00 is to the right, 9:00 is to the left and 12:00 is the back. The outlet can go at 3:00, 6:00, 9:00 or 12:00; inlets and overflows go at 3:00, 9:00 or 12:00, since 6:00 is where the logo goes. Generally, do not put the overflow above the outlet: if you plumb the overflow, the pipe comes down where your outlet is. Point the overflow so it carries water away from the tank and the house toward a low-lying area.

Which outlet size should I choose?
Texas Metal Tanks says most tanks 1,000 gallons or less get a 3/4″ bulkhead, which accepts a 3/4″ spigot for a garden hose. If you will pressurize the water with a pump now or later, choose a 1-1/4″ or 2″ bulkhead; you can always reduce it with a bushing.

How does the basket inlet work?
The stainless steel screened basket sits in the top of the tank near the edge. You turn the top so the basket is under the downspout, then secure the top in place. The fine mesh keeps debris and mosquitoes out. Texas Metal Tanks notes a basket inlet is often the easiest choice when the tank collects from one downspout.

PLANNING YOUR SYSTEM

How big a tank do I need?
Start with what you will use the water for; Texas Metal Tanks notes irrigation is often the largest household use. One inch of rain on 1,000 sq ft of roof produces about 600 gallons, and Texas Metal Tanks recommends sizing a system to hold a 2″-3″ rain event. By that rule this 500 gallon tank suits roughly 280-420 sq ft of roof, and a 1″ rain on about 830 sq ft will fill it. For larger roofs, consider multiple tanks.

Will it fit my space?
Allow for the 48″ diameter plus a base about a foot wider, and the 68″ sidewall plus the top. Texas Metal Tanks notes that seven-foot-tall tanks work well under eight-foot eaves. Check for trees, fences and gate widths: tanks are bulky, should not be lifted by hand, and need a clear path to the pad.

Are there rebates for rainwater harvesting?
Many municipalities offer rebates, often $0.50 to $1.00 per gallon of storage. Some require pre-approval before you buy and install the tank, so check with your city or water utility first.

Can my HOA stop me from installing a tank?
In Texas, a 2013 law prohibits HOAs from banning rainwater harvesting systems (Texas Property Code Sec. 202.007). An HOA may limit where the tank goes, but it must allow rain barrels and rainwater tanks. Rules in other states vary.

DESIGNING YOUR SYSTEM

What inlet and overflow size should I choose?
Texas Metal Tanks recommends matching the overflow size to the inlet size so water moves through the system easily. A tank of 1,000 gallons or less usually collects from one downspout, where a 3″ inlet is typically fine; with 6″ gutters, or several downspouts piped together, go to a 4″ inlet.

How do I keep leaves and debris out?
If your gutters clog with leaves, the tank will too when water runs straight in. Gutter screens are the first line of defense, a stainless steel basket inlet on the tank helps, and where neither works Texas Metal Tanks recommends a first flush diverter.

Can it be pressurized, or do I need a pump?
The tank itself cannot be pressurized. Texas Metal Tanks tanks are not designed to hold pressure; they are self-venting. To pressurize water for the house or an irrigation system, use a pump after the outlet; Texas Metal Tanks notes that pressurized systems inside city limits need backflow protection devices. A submersible sump pump is another option.

INSTALLING YOUR SYSTEM

What kind of base does it need?
The tank must sit on a solid base that supports the entire bottom. Texas Metal Tanks recommends 2″-3″ of tamped crushed granite inside a frame about a foot wider than the tank; limestone block, brick, pavers or a concrete pad also work. Water weighs 8.3 lb per gallon, so a full 500 gallon tank holds about 4,150 lb of water.

How do I move the tank into place?
Large tanks slide easily across 2 x 4s or, better, PVC pipes. A tank can also be tipped onto its bottom edge and rolled. Do not lay a large tank on its side and roll it.

What can I connect to the bulkhead?
The bulkhead is threaded inside and outside. Fittings screw only into the inside threads; the outside threads are reverse threaded and only accept the locknut. For example, a 3/4″ bulkhead accepts a 3/4″ spigot.

How is the top attached?
The top is held on by four self-tapping sheet metal screws. Texas Metal Tanks recommends pre-drilling the holes about 1-1/2" from the edge. Tanks do not ship with the top screwed on. The top is secured once the tank is in place so it cannot blow off.

Can I paint the PVC fittings?
Yes. Texas Metal Tanks suggests a metallic gray spray paint so the PVC inlet and overflow match the look of the tank.

ABOUT THE TANK

Is it safe for drinking water?
Yes. Texas Metal Tanks states all of its tanks are suitable for potable water. The interior paint / epoxy lining is FDA approved and ANSI / NSF 61 certified.

How long does it take to ship, and what warranty does it have?
The manufacture lead time is 5-8 weeks and the tank ships from Texas. Texas Metal Tanks lists a 1 year warranty on its galvanized steel cisterns.

Manufacturer Documents

• Texas Metal Tanks product page: Galvanized Steel Rainwater Tank
• Texas Metal Tanks sizes, pricing and fittings information
• Texas Metal Tanks rainwater system design and installation guide

Shipping and Warranty

• Manufacture Lead Time: 5-8 Weeks
• Ships From (State): TX
• Manufacturer Warranty: 1 Year (Texas Metal Tanks)

Products are subject to freight or parcel shipping costs. Shipping charges are calculated at checkout based on delivery location, product size, weight, and carrier requirements.

Warranty Information
Texas Metal Tanks lists a 1 year warranty on its galvanized steel cisterns. For warranty details or to initiate a warranty claim, please contact Tank Supply Direct at info@tanksupplydirect.com.