Water Softeners

What is a water softener?

A water softener is a filtration system that removes hardness-causing calcium and magnesium minerals from water through a process called ion exchange.

A water softener is made up of three main components: a softener control valve, a resin tank, and a brine tank. These three works in conjunction to remove the minerals from hard water, monitor the flow of water, and periodically clean the system through a regeneration process.

Allmech has extensive experience in designing, building and operating small, medium and large scale water softeners. We offer cost effective environmentally friendly water treatment solutions.

How to calculate water hardness

Hardness is caused by compounds of calcium and magnesium, and by a variety of other metals. General guidelines for classification of waters are:
WP Data Tables
Water Softeners

If you do not have water test result indicating the water hardness. Water hardness is calculated as CaCO3. The water hardness is using American degree equivalent to mg/L. To calculate your water hardness, you would need Calcium (Ca) count in ppm or mg/L as well as Magnesium (Mg) count in ppm or mg/L.

Hardness formula          = (Ca mg/L x 2.497) + (Mg mg/L x 4.118)
                                            = hardness as ppm CaCo3

How do water softeners work?

Water softeners work through a process called ion exchange which eliminates calcium and magnesium from the water. Hard water enters the softener vessel and flows through the resin tank bed of resin beads. These beads are charged with a sodium ion. The resin beads are anions, meaning they have a negative charge. The calcium and magnesium minerals have a positive charge, making them cations. Since opposite charges attract, the negative charge of the minerals is attracted to the positive charge of the resin beads. As the hard water passes over the resin, the mineral ions attach to the beads and thus removes them from the water.

When the beads become saturated i.e. cannot accept any more ions, the water softener regenerates by cleaning the hard minerals off the beads and draining the wastewater. Here brine from the brine tank which is saturated with sodium (Na+) enters the resin tank, where polymer beads attract the sodium molecules and discard the calcium and magnesium in waste water. Water softener regeneration cycle time is about one and a half hours.

At this point, the cycle starts over again.

Water Softener Cycle

What are the main components of a water softener?

  1. The resin tank

    The resin tank is the chamber where the hard water is softened. The water supply line feeds the hard water into the tank. The water seeps through the bed of resin beads, depositing the water-hardening calcium and magnesium ions. The water exits the tank soft.  Allmech offers a range of FRP (Resin) tanks ranges from : 7 x 35 to 48 x 72.

Allmech water softening resin

Lonizable groups attached to the resin bead determine the functional capability of the resin. Industrial water treatment resins are classified into four basic categories: Strong Acid Cation, Weak Acid Cation, Strong Base Anion and Weak Base Anion.

  1. The control valve

    Control valves are demand-initiated controllers, which allow water softening units to be extremely efficient. The control valves have 5 main functions: Service, Backwash, Brine and slow rinse, Brine refill and Fast rinse.

Allmech is the sole agent for Runxin water treatment system valves in the South Africa. We supply a full range of manual and automatic filter and softener valves. The valves are reliable, easily available, user-friendly and cost effective.

The valves have proven to be more chemical resistant and robust than other brands on the market. Allmech is fully equipped to test, service and repair these valves locally.

  1. The brine tank

    The brine tank aids the water softening system in regeneration. The brine tank holds a highly concentrated solution of salt to restore the resin beads’ positive charge. Salt is manually added to the brine tank. The salt dissolves in the water at the bottom of the tank. When the control valve registers the softening capacity of the resin is diminishing, the brine solution is drawn out of the tank and flushed through the resin in the mineral tank. If the brine tank runs out of salt, the water passing through the unit will no longer be softened. Allmech offers brine tanks ranging in size from 50 lts to 2000 lts.

Types of Salt

There are different types of salt available for water softeners. The choice depends upon the type of water softener and manufacturer design. Softeners are designed to use specific types of salt so it is important to follow manufacturer’s recommendations regarding the salt type.

What are the key considerations?

  1. Daily consumption of water on site
  2. Maximum flow rate per hour required
  3. Hours of operation
  4. Water hardness as CaCO3 (mg/L)
Duplex Softener

Advantages of a water softener system:

A well-designed water softener system only removes the minerals causing hardness. Due to high levels of calcium and magnesium, many types of equipment fail to work properly or efficiently, which can lead to an increase in energy costs and/or complete failure of the equipment.

Advantages include:

  • Consistent feed water quality
  • Reduced fouling and corrosion of equipment
  • Reduced maintenance costs
  • Overall cost savings in the long run
  • Equipment operation excellence
  • Improved energy performance of equipment

Disadvantages of a water softener system:

If the problem with the incoming water is more than high levels of minerals, water softening will not help. Water softeners do not disinfect the water; they do not address most problems with taste and smell of organic sources. Salt-based water softening systems require a regular maintenance and replenishment schedule, which causes higher expense.

Operation and Maintenance

The softener must be kept regenerated to avoid hard water flowing into pipes and appliances. Maintenance of water softeners are largely confined to restocking the salt supply for the brine solution.

The brine tank may require periodic cleaning. The frequency of cleaning depends on the amount and purity of the salt used in the softening process. The brine valve and float assembly also should be checked and cleaned as often as needed.

In certain situations such as high concentrations of iron or manganese in the water, it can affect the exchange capacity of the resin. In this case the resin may eventually need to be cleaned or replaced. A water treatment professional should be consulted for guidance on cleaning or replacing the resin.

Adequate backwashing of the resin bed is important to ensure efficient regeneration of the unit. If backwashing is to be done manually or is semiautomatic, the backwash should be continued until the water runs clear. If the unit is fully automatic and backwash time is adjustable, adjust the time so the backwash is long enough to produce clear water in the drain.

Water softeners need maintenance visits on a regular basis to keep them at a good operating level. Allmech offer our valued customers a monthly maintenance service visit which includes:

  • Water analysis report on key parameters for raw water, soft water, feed water
  • Boiler or Cooling tower analysis on key operating parameters
  • Equipment analysis and adjustments when required
  • Repair of wear and tear items
  • Repair of faulty items
  • Delivery of chemicals and salt
  • Upgrades of systems
Softener Operator
Duplex Softener
Duplex Softener

Repair and service of softener control valve

Allmech is fully equipped to test, service and repair softener control valves locally. We offer a wide range of spares and parts on our Runxin water softener control valves. We are able to support various other makes of softener control valves for easy repair.

Please contact Allmech for technical advice on your water softener control valves repair and maintenance requirements.

F63 Exploded view

Industrial Water Softening

Due to high levels of calcium and magnesium, many types of equipment fail to work properly or efficiently, which can lead to an increase in energy costs or failure of the equipment.

Many plants use water softeners for boiler feed, cooling towers, entire water supply and various types of process water. Industries that have a high usage of water and need for treatment include: brewery and carbonated beverage water; dairy industries; sugar mills and refineries; textile manufacturing; pulp and paper mills; oil and gas; the automotive and aircraft industries and many others.

Industrial water use includes water used for such purposes as fabricating, processing, washing, diluting, cooling, or transporting a product; incorporating water into a product; or for sanitation needs within the manufacturing facility.

The correct balance of minerals of incoming water to industrial systems is essential to the proper operation and maintenance of expensive equipment.

Boiler Operations

A water softener removes hard water minerals, like calcium and magnesium, which can cause scaling and damage in the boiler tubes. Acting as an insulator, scale deposits can prevent proper heat transfer, decrease boiler efficiency, and lead to costly downtime and even premature boiler failure.

When using water softeners for boiler feed water, there are several factors that must be considered in the design:

  • What our the daily consumption of water
  • Maximum flow rate per hour required
  • Hours of operation
  • Water hardness as CaCO3 (mg/L)
  • Condensate return if on boiler
  • Boiler steam output
  • Incoming raw water pressure

In order to successfully treat boiler feed water, to minimise or eliminate problems, requires a planned programme. It is important to select the correct type of treatment to suit the installation needs.

The main purpose of boiler feed water treatment is to prevent:

  • Scale deposits
  • Corrosion
  • Foaming and carry-over

Why do we need to do water treatment for boilers?

  • To protect plant and equipment
  • To prevent scale and corrosion
  • To increase boiler efficiency
  • To reduce downtime
  • To reduce maintenance costs

Scale in your boiler can cause:

  • Poor heat transfer
  • Hot spots and tube failure
  • Under deposit corrosion
  • Reduced boiler efficiency

Corrosion in boiler can cause:

  • Poor heat transfer caused by corrosion products
  • Plant and equipment failure
  • Increased down time
  • Increased maintenance cost
Boiler Operation
Water Softener Operation
Boiler Operations
Boiler Operations

Cooling Tower Operations

Cooling towers are another common application for industrial water softeners.  Cooling towers can operate much more efficiently with softened water. This can help to realize a drastic reduction in maintenance, chemical feed quantity, and the volume of water required for operation.

Flow rate and capacity are major concerns when designing a softening system for a cooling tower.  A thorough understating of daily water usage and required flow rates are critical.

Please contact Allmech for a full analysis and recommendation on your water softener requirements.

Cooling Tower Operation

Allmech Water Softener Range

We supply water softeners to the boiler industry at competitive prices. The high-quality resin used in our softeners saves on the cost of brine in regeneration.

Simplex Units

Simplex Water Softeners are ideal for large residential and light commercial applications such as large homes, laundry facilities, restaurants, hotels, commercial boilers and so on. They are ideal for when moderate volumes of softened water are required during the normal course of a day, where usage does not occur 24/7.

WP Data Tables
Cooling Tower Operation

Simplex water softeners are best sized such that at the very least, one working day of softened water is made available before the system requires a regeneration. Regeneration is programmed to occur at a time when there is no demand (typically during the night). The cycle can be programmed to occur according to water hardness and the volume of water used between cycles. Regeneration can also be made manually as and when required.

We offer top quality, reliable and cost-effective water softeners. We can assist with a complete turnkey water treatment program, including chemical dosing.


Duplex softeners are designed to supply softened water in situations where a continuous and uninterrupted supply of soft water is required. These systems therefore have a double tank, so that there can always be one tank in service while the other tank is able to regenerate, thereby ensuring a 24/7 soft water supply.

Use the table below to compare the performance of each model in our Duplex Water Softener range:

WP Data Tables

Duplex Unit