Experts' Guide to Selecting and Purchasing Vertical Coil Tanks
DamaTajhiz vertical coil water heaters are manufactured from Iranian hot-dip galvanized ST37 steel sheets designed for high-pressure tanks, by standards 17 MN4 and DINI17155. The 600-liter vertical coil tank body is available in 4 mm and 5 mm sheet thickness options, both of which are manufactured by DamaTajhiz. Compared to double-walled tanks, coil tanks provide faster and more powerful hot water supply.
Before ordering a hot water tank, make sure it can fit through the mechanical room door and that there's adequate space for installation and operation. If you require a custom size, please specify it when placing your order.
At the specialized and trusted DamaTajhiz marketplace, you’ll find technical specifications and the best prices for coil tanks and other types of water tanks—all with original warranties—to ensure an optimal and smart purchase experience.

DamaTajhiz – Thousands of Products for Thousands of Projects (Since 2004)
Features of the 600-Liter Vertical Coil Tank by DamaTajhiz
- The dish heads of this 600-liter vertical coil tank are flanged for extra strength.
- The tank body includes 4 welded sockets for connecting relevant piping as follows:
- Cold water inlet socket
- Hot water outlet socket
- Hot water return socket
- Temperature-pressure relief valve socket
Important Notes When Ordering DamaTajhiz Vertical Coil Water Tanks
- The listed height does not include the base of the tank.
- A minimum clearance of 30 cm is required between the top of the tank and the mechanical room ceiling.
- When purchasing coil tanks, pay attention not only to capacity but also to the body material, sheet thickness, and coil heat exchange surface area.
- All vertical coil tanks from DamaTajhiz come with a specification plate (model, capacity, production year), a 15-month golden warranty from DamaTajhiz, and 10 years of after-sales service.
- For tanks over 1500 liters, an inspection manhole is available upon customer request and with mention in the invoice.
- The hot water or steam coils in DamaTajhiz vertical tanks are produced according to valid standards and in proper thicknesses—typically 0.7 mm for hot water coils and 0.9 mm for steam coils.
- The sheet thickness of DamaTajhiz coil tanks can be manufactured up to 16 mm depending on the capacity and working pressure. (Note: Appropriate standard welding methods are used for thicker sheets.)
- Accurate calculation of the required DamaTajhiz coil tank volume, sheet and dish head thickness, dimensional check for mechanical room access, and correct coil size and surface area is essential.

DamaTajhiz – Thousands of Products for Thousands of Projects (Since 2004)
Calculating the Required Capacity of a Vertical Coil Water Heater Tank
To estimate the required capacity of a coil water heater tank for a building, you should consider the number of residential units, type of building usage, demand factor, simultaneity factor, and consumption coefficient. On average, an approximate capacity of 100 to 200 liters per unit is considered for coil or double-walled water heater tanks.
Hot Water Tank Capacity for Quick and Approximate Calculations
| Building Type |
Tank Capacity (Liters) |
| Residential (up to five residents) |
189 – 283.5 |
| Residential (over five residents) |
472.5 |
| Apartment Complexes with Shared Tank |
189 per apartment unit |
| Hospitals (per bed) |
46 |
| Schools (per student) |
1 – 2 |
| Offices (per employee) |
4.7 |
| Factories (with shower needs, per worker) |
28.3 |
| Source: Building Services Calculation Manual |
- Using plate heat exchangers to supply domestic hot water is only permitted if the building's boiler room is equipped with a water softener system.
- When using a vertical coil water heater to supply hot water, a suitable circulation pump must be installed to circulate the boiler’s hot water through the tank coil.
- To calculate the heat exchange surface area of the coil inside the tank, a general rule is to divide the total heat required (based on tank volume and temperature difference between cold inlet and hot outlet water) by the product of the overall heat transfer coefficient (U of coil material) and the logarithmic mean temperature difference of inlet and outlet water.

Advantages of Coil Water Heaters Compared to Double-Walled Tanks
- Coil water heaters, available in vertical and horizontal models, are used to produce sanitary hot water from cold water in central heating systems.
- The heating mechanism of coil tanks is based on transferring the thermal energy of hot water or steam (from the central boiler) via a built-in coil to the cold water inside the tank—similar to a heat exchanger.
- Compared to double-walled tanks, coil tanks offer easier maintenance due to their single-walled design (in case of leakage), faster heating of cold water, and higher efficiency thanks to the internal coil (or heat exchanger).
- Coil water heaters are available in vertical and horizontal types, calculated and manufactured based on project specifications, and are used in boiler rooms of hotels, hospitals, residential and office complexes, factories, swimming pools, etc., with valid warranties.

Installation Tips for Vertical Coil Water Heater Tanks
- It is essential to install a concrete foundation with appropriate dimensions and a maximum height of 10 cm to ensure stable and level positioning of the vertical coil tank in the boiler room.
- Installing a temperature and pressure relief valve is mandatory for all domestic hot water production tanks, including coil tanks.
- Schematic piping layout for vertical coil water heater tank:

Order and Warranty for DamaTajhiz 600-Liter Vertical Coil Water Heater
- The DamaTajhiz 600-liter vertical coil water heater comes with a 15-month golden warranty and 10 years of after-sales service.
- DamaTajhiz Engineering Company offers the technical specifications and guaranteed prices of various vertical coil water heater tanks along with a golden warranty to ensure you enjoy an optimal and smart purchase experience.
- DamaTajhiz designs and manufactures its tanks in compliance with all engineering principles and global standards, confidently ensuring high product quality and a pleasant customer experience.
- All prices for DamaTajhiz vertical coil water heater tanks listed on the specialized reference platform are up to date, including potential discounts for clients. These prices are covered under DamaTajhiz's Best Price Guarantee policy. (Refer to the Best Price Guarantee section for more details.)