How to calculate Septic Tank Size.

This is a question where almost all engineers ask while interviews.

HI Viewers I am Afreen Ali . I brought this video for How to calculate Septic Tank Size. Kindly Subscribe my channel

AfreenAli

Calculation Septic Tank Size

An undersized septic tank exceeds its holding capacity, sewage can back up into your home, so when you're putting in a septic tank, it's essential that you take the time to calculate the correct size. Most municipalities require even the smallest septic tanks to hold approximate 1,000 gallons. The required capacity increases from there based on the number of bedrooms, occupants, bathrooms and fixtures the septic system will service.

 

Firstly

Calculate the number of occupants who will be regularly using your septic system. If you have a two-bedroom house, for example, most municipalities assume the house will have four regular occupants. A three-bedroom house assumes six occupants.

 

Secondly

Count the number of bathrooms that the septic tank will service. If you only have one bathroom but anticipate you may put in another one down the road, include the second bathroom in your count to prevent having to replace your tank later.

 

Thirdly

Count the number of plumbing fixtures in your house. This figure includes all taps, toilets, showers, dishwasher, clothes washer and any other fixture that will drain into your septic tank.

 

Finally

Take your calculations to your local permit office to check them against your local regulations in order to determine appropriate septic tank sizing. Sizing rules vary slightly from location to location. In Dubai, for example, a three-bedroom house with two bathrooms and roughly 20 fixtures requires a tank of at 1,250 gallons. A building with 14 occupants and three to five baths requires a 2,000-gallon tank.

How to calculate head pressure of pump for a CHW system.

 How to calculate head pressure of pump for a CHW system. This is a question where almost all engineers ask while interviews.

HI Viewers I am Afreen Ali . I brought this video for How to calculate head pressure of pump for a CHW system. Kindly Subscribe my channel

There are 2 types of heads

Static head which is due to height difference - second is Dynamic head which is due to the losses while flow like losses in pipe due to friction, bends and due to piping accessories like vaves coils etc.

As chilled water systems are closed loop so the static head is zero in the chilled water system (NOT FOR COOLING TOWR IF APPLICABLE BECAUSE CONDENSER PUMPS FOR COOLING TOWERS ARE OPEN CIRCUIT). 

So the pressure for CHW System will be calculated by adding all the piping in the maximum pressure drop route and add friction losses, bending and coil losses, losses in equipments etc thus adding all of them will give you the pressure head.

Example 

Two different pressures. All friction losses are for pump capacity sizing. Basically how much water the pump can pump. This would be the same if the same piping system is 900 ft high, or 900 ft wide. 

The static pressure depends on height and is important for selection of equipment, relief valves etc. so it doesn't "explode" at the highest pressure. You need to imagine the hydro-static pressure + the pump pressure at tha tlocation. Pump pressure at pump suction side is zero, at discharge the max what the pump can do (assume someone overrides the VFD).

Consider gravity of fluid. for water every 2.3 ft you increase by one psi. this will be less for lighter fluids, more for denser fluids.