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2018-10-20

What is De coupler line?

What is De coupler line?

Decoupler (Decoupler bridge) used for the piping design between the primary and secondary loops, the purpose of it is to have a minimum pressure drop, thus any change in flow rate in one loop will not affect the flow rate at the other.

What is chiller Decoupler?

Primary-Secondary (decoupled) chilled water systems contain a primary pump loop through the chillers and a separate secondary pump loop through the cooling coils.

What is the function of primary and secondary pumps in chilled water system?

The primary loop uses a constant speed pump to circulate the working fluid (water). The secondary loop uses a variable speed pump to manipulate the flow of the fluid such that the cooling coil demand is satisfied.

How does a primary secondary loop work?

The primary loop simply becomes the source of hot water (as opposed to a direct connection to the boiler or a holding tank). The primary loop also becomes the pressure reference point for the secondary circuit. In effect it acts like an expansion tank for the secondary circuit.

What is primary and secondary loop?

The flow from the primary pump (100 GPM) is going straight through both tees and the water in the secondary loop is just sitting there. All the action is in the primary loop. This is the basis for another common hydronic rule: When two piping circuits are interconnected, flow in one will NOT cause the flow.

What is a secondary loop?

“A secondary loop refrigeration system incorporates two different refrigerants to provide cooling.

What is primary flow and return?

With an indirect water system, the copper hot water cylinder contains a coil of pipe. This heating is called the “primary” circuit, the pipes running to and from the boiler are called the primary flow and return. The hot water tank operates in exactly the same way as the direct system.

What is a primary heating circuit?

An assembly of water fittings in which water circulates between a boiler or other source of heat and a primary heat exchange inside a hot water storage vessel, and includes any space heating system.

What does a hydraulic separator do?

A hydraulic separator reduces flow velocity, in the vessel, which allows for two secondary functions – air removal and dirt removal – in one device. 3-in-1 hydraulic separators make air removal and dirt removal primary functions, along with hydraulic separation, with no added piping connections or installation costs.

What is hydraulic decoupling?

This is known as decoupling or hydraulic separation. To decouple or hydraulically sepa- rate one circuit from another, an area of very low pressure drop must be created in the common piping between the two circuits. This pipe is sometimes referred to as the decoupler or hydraulic separator.

What is hydraulic separation method explain it with diagram?

Hydraulic separation method : The hydraulic separation method is based on the working of a mill. This is a tapering vessel similar to that used in a grinding mill. It opens in a tank-like a container that is tapering on the lower side.

What is inside a low loss header?

A low loss header usually has a drain at the bottom of it. Hot water passes through the header at a lower pressure than it would pass through the rest of the system. This reduction in pressure and speed allows time for any dirt and debris in the system to sink to the bottom of the header.

How do I choose a low loss header?

The header should be sized so that the pressure loss at full flow is small. All secondary circuit flows and the flow from the boilers should normally be at the top, or one end of the header. All secondary circuit returns and the return to the boilers should be at the bottom, or other end of the header.

When should a low loss header be used?

A low loss header is typically used as ‘hydraulic separation’ between any two or more circulating pumps within a heating system. This hydraulic separation allows each pump to work independently at their own flowrates without pulling or pushing on the other.

How do you size a low loss header?

The length of your low loss header should then be a simple calculation based on 4 x diameter. This is the minimum separation between your flow and return and, again, you can size up.

What is a reverse return heating system?

A reverse return system is a type of closed loop system where the return header is connected to the most hydraulically remote load, as shown in Image 1. Image 4 shows the calculations for an identical system with the exception of an additional length of piping on the return header to create a reverse return system.

What is a header in plumbing?

The term “header” has been around the hydronics industry long before I got here. It refers to a piping assembly that divides an entering flow stream into two or more branches. Just connect some tees together with short lengths of pipe to build a supply or return header that stretches out a few feet across the wall.

What is a shunt pump?

The boiler shunt pump circulates the water from the flow pipe into the return pipe or directly into the boiler. For certain types of fuel, very low temperatures can cause corrosion at the bottom of the boiler.

What is the purpose of a shunt pump?

A high temperature difference can cause tensions in the material and thus reduce the life of the boiler. The boiler shunt pump circulates the water from the flow pipe into the return pipe or directly into the boiler.

Why is a shunt pump fitted to a calorifier?

The destrat / shunt pump alone ensures a uniform temperature throughout the calorifier, and if that uniform temperature turns out to be below 60C then the demand signal is generated to make the boiler fire anyway.

How often should Showers be cleaned and chlorinated?

every three months

How often should a cold water tank be checked?

When to clean Potable cold water storage tanks need to be cleaned more regularly because they feed drinking water outlets. The temperature of the tank from the inlet and outlet should be inspected at least annually.

What is Legionella?

Overview. Legionnaires’ disease is a severe form of pneumonia — lung inflammation usually caused by infection. It’s caused by a bacterium known as legionella. Most people catch Legionnaires’ disease by inhaling the bacteria from water or soil.

How serious is Legionella?

Legionnaires’ disease is a serious, life-threatening illness that requires prompt treatment. Legionella may also cause a milder condition referred to as Pontiac fever. Pontiac fever doesn’t cause pneumonia and isn’t life-threatening. It has symptoms similar to those of a mild flu, and it usually goes away on its own.

What are the first signs of Legionnaires disease?

The symptoms of Legionnaires’ disease are similar to the symptoms of the flu:

  • high temperature, feverishness and chills;
  • cough;
  • muscle pains;
  • headache; and leading on to.
  • pneumonia, very occasionally.
  • diarrhoea and signs of mental confusion.

How do you test for Legionnaires disease?

The most commonly used laboratory test for diagnosis of Legionnaires’ disease is the urinary antigen test (UAT), which detects a molecule of the Legionella bacterium in urine. If the patient has pneumonia and the test is positive, then you should consider the patient to have Legionnaires’ disease.