Your reliable partner for alkalizing agents & pH control in water and steam systems

The pH value has a significant influence on the rate of corrosion, the formation of deposits and the chemical effect in water systems.

• Zu niedriger pH (<7): fördert Säurekorrosion, insbesondere an Stahl, Kupfer und Aluminium

• Too high pH (>10-11): can promote limescale precipitation, attack aluminum and inactivate biocides

• Optimum ranges: vary depending on the application, e.g. 8.5-9.2 for boiler water, 9.5-10.5 for district heating and 7-8.5 for cooling water

The targeted pH adjustment with alkalizing agents not only protects the system, but also complies with standards such as VDI 2035, VDI 2047 and PED.

ALMA AQUA offers three main groups:

1. Volatile alkalizing agents - e.g. morpholine, cyclohexylamine, DEAE

   • Acting in the steam and condensate area

   • Suitable for steam systems, boiler systems

2. Semi-volatile amines - e.g. methoxypropylamine

   • Longer dwell time, effective in mixed systems

3. Non-volatile alkalizing agents - e.g. sodium hydroxide, potassium hydroxide

   • Only effective in the water area, ideal for cooling and district heating networks

The choice depends on the system type, temperature, pressure, material and O₂ management.

Signs of pH problems are

• Traces of corrosion on pipes, heat exchangers or valves

• Copper deposits in the system (indication of copper corrosion)

• Fluctuating measured values despite constant water treatment

• Poor efficacy of inhibitors or biocides

• Elevated iron or copper values in water analyses

An on-site pH measurement or laboratory analysis provides the exact status - deviations from the normal range are a clear signal to use alkalizing agents.

Volatile alkalizing agents (e.g. morpholine, DEAE) evaporate with the steam flow and condense in the condensate, which also protects return lines from acid corrosion.
Advantages:

• Protection of the entire steam/condensate system

• Uniform pH distribution in all lines

• Reduced return flow corrosion in condensate systems

An incorrect pH setting can cause gradual but massive damage to water systems. The effects depend heavily on the type of system and the material mix:

• Zu niedriger pH (<7,5 im Kesselwasser, <8,5 im Fernwärmenetz):

  • Acid corrosion on steel, cast iron and copper (pitting, uniform surface erosion, hydrogen embrittlement in steel)

  • Increased copper dissolution, which in turn attacks steel through copper plating

  • Accelerated dezincification for brass

  • Chemical attacks on cement and concrete linings

• Too high pH (>10.5-11, depending on application):

  • Precipitation of calcium carbonate (CaCO₃) → Heat exchanger losses due to lime

  • Formation of calcium and magnesium silicates → poorly soluble deposits

  • Attack on aluminum and its alloys

  • Restriction of the effectiveness of many biocides (e.g. isothiazolinones)

In addition to direct damage, there may also be economic consequences:

• Increasing energy consumption due to coatings (1 mm lime = up to 10 % more energy requirement)

• Increased chemical consumption, as additives are less effective at the wrong pH

• Shorter system downtimes and more frequent repairs

• Standard violations (VDI 2035, VDI 2047, PED) that can lead to complaints during audits

The dosage of an alkalizing agent must be precisely matched to the system situation. Important factors are

1. Water analysis:

   • Determination of raw water pH, acid capacity (KS₄,₃), CO₂ content, total hardness and conductivity

   • Measurement of the current buffer capacity to calculate the required amount of active ingredient

2. System parameters:

   • System volume and turnaround time

   • Operating temperature and pressure (influence evaporation behavior with volatile amines)

   • Material mix (steel, copper, aluminum, stainless steel)

3. Target pH:

   • Depending on the type of system and the standard specifications (e.g. VDI 2035 for boiler water)

4. Dosing strategy:

   • Continuous dosing with pH feedback control for constant values

   • Impulse dosing with occasional pH correction (rarely useful for large systems)

Our specialist engineers often use online pH measuring systems with trend recording and alarm function.
This allows the dosing quantity to be automatically adjusted to load changes, which enables chemical and cost-efficient operation.

Yes - our products are tailored to:

• Corrosion inhibitors (phosphates, molybdates, silicates, azoles)

• Antiscalants & hardness stabilizers

• Oxygen binder

• Biocides & dispersants

Compatibility is checked at the product selection stage in order to avoid interactions.

The use of alkalizing agents in industrial water systems must comply with several regulations and laws:

• VDI 2035 (sheets 1 & 2) - Specifies target pH values for heating water and boiler systems to prevent corrosion and scale formation.

• VDI 2047 - For evaporative cooling systems: pH control is crucial for biocide effectiveness and material protection.

• PED (Pressure Equipment Directive) - Refers to the choice of materials, mode of operation and chemical treatment of pressure equipment such as boilers and heat exchangers.

• Drinking water ordinance / BfR recommendations - If systems come into contact with drinking water (e.g. storage tank charging systems), only tested and approved active substances must be used.

• TA Luft & WHG - regulates the handling and discharge of wastewater; high pH values are subject to approval and often require neutralization.

• Food hygiene regulations (HACCP, FDA) - Additional requirements for product purity and documentation apply to applications in the food or pharmaceutical industry.

We supply complete safety data sheets (SDS), technical data sheets (TDS) and references to regulations - and also provide declarations of conformity for audits if required.

Our alkalizing agents are used in a wide range of applications - always adapted to the type of system, material and water chemistry:

1. Boiler feed water & steam generator

   • pH increase in feed and boiler water

   • Use of volatile amines to protect the entire steam/condensate system

   • Prevention of acid corrosion in condensate returns

2. District heating & hot water systems

   • Stabilization of high pH values (9.5-10.5) for optimum steel and copper protection

   • Use of non-volatile alkalizing agents (e.g. NaOH, KOH)

   • Support of the corrosion inhibitor system

3. Cooling water circuits

   • pH optimization for maximum effectiveness of corrosion inhibitors and antiscalants

   • Adjustment for CO₂ entry or acidic make-up water

4. Process water applications

   • Paper industry: pH stabilization for process consistency

   • Chemical industry: adaptation for reactive production processes

   • Food industry: Use of BfR/FDA-compliant alkalizing agents

5. RO membrane systems

   • pH adjustment to prevent deposits (e.g. silicate precipitation)

   • Preparation of cleaning cycles through pH shifting

Whether in closed heating systems, open cooling circuits or highly sensitive process applications - pH control is always a key parameter for trouble-free, energy-efficient and standard-compliant operation.