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The Question & Answer (Q&A) Knowledge Managenet

The Internet has many places to ask questions about anything imaginable and find past answers on almost everything.

Table of Contents

- How can you decrease pressure in a closed container?
- When volume is halved what happens to pressure?
- What are the factors which are responsible for causing pressure in a container?
- What three factors can affect pressure?
- Does pressure increase in smaller pipe?
- How does flow rate change as a pipe becomes smaller?
- What size pipe should I use for irrigation?
- How does pressure change in a pipe?
- Does pressure decrease with pipe diameter?
- Is pressure the same in a pipe?
- How do you reduce pressure in a pipe?
- What is reduces in size by pressure?
- How do you increase pressure in a pipe?
- What is pressure drop in gas piping?
- What is a high pressure drop?
- What is the formula for pressure drop?
- How do you convert pressure to head?
- Does pressure drop increase with velocity?

Amount of substance is constant, the gas constant R is obviously a constant, and it’s a closed container so volume V is also constant. So with V, n and R all being constant, P is proportional to T. In other words, reduce temperature = reduce pressure.

If volume increases, then pressure decreases and vice versa, when the temperature is held constant. Therefore, when the volume is halved, the pressure is doubled; and if the volume is doubled, the pressure is halved.

An increase in the number of gas molecules in the same volume container increases pressure. A decrease in container volume increases gas pressure. An increase in temperature of a gas in a rigid container increases the pressure.

The three factors affecting the gas pressure are temperature of the gas, volume of the gas and the number of particles in the gas. Increasing any of these factors will result in an increase in the gas pressure.

The more tightly you squeeze your thumb, the more you’ll see reduced flow and feel greater pressure. A smaller pipe would lessen the flow of water as well as reduce the pressure loss in the pipes. This in turn would cause more pressure but render a sprinkler system inoperative.

Flow rate varies inversely to length, so if you double the length of the pipe while keeping the diameter constant, you’ll get roughly half as much water through it per unit of time at constant pressure and temperature.

For schedule 40 PVC, use 1/2-inch pipe for a 4 GPM system, 3/4-inch pipe for 8 GPMs, 1-inch pipe for 13 GPMs, 1 1/4-inch pipe for 22 GPMs, 1 1/2-inch pipe for 30 GPMs, and 2-inch pipe for 50 GPMs.

As described above, the pressure on a fluid at a point in a piping run changes with the elevation of the fluid. As the fluid rises there is a pressure loss and as it falls there is an equivalent pressure gain (for the same change in elevation).

When the diameter of the downstream pipe decreases, the pressure of the upstream pipe increases. Therefore, the pressure at the reduced pipe diameter is lower than that at the upstream.

So the pressure difference is proportional with difference in height, and for all points at the same height the pressure will be the same. Dynamic pressure will be lower for the #2, as there won’t be the same pressure loss due to the resistance difference.

To reduce the pressure in a pipe in the long run (without installing a pressure relief system), you need to reduce the ration of fluid to pipe at any given moment. That means, 1. you actually reduce the amount of fluid going into the system, or 2. you increase the pipe size of the system.

Pressure is a force applied in a certain area. The force applied causes compression on a certain material. This compression causes the particle of atom to be more compact and more compressed which result in reduction of size. All matters can be compressed because of pressure and would result to size reduction.

To adjust pressure, the diameter or texture of the pipe must be altered using a different regulator/pump or regulator/pump setting. The water pressure can also be adapted by changing the amount of water that is raised above the water that is coming through the water line.

Pressure drop can be defined as the quantity of line pressure, which is lost forever when gas flows through a device in a gas line. This loss of pressure is due to the frictional resistance of the parts exposed to the gas. Each instrument and fitting in a line causes a certain amount of drop in pressure.

The higher the pressure drop in the line, the greater the amount of energy consumed to maintain the desired process flow, requiring a higher horsepower motor. Conversely, the lower the pressure drop in a piping system, the less energy consumed, providing the potential to use a lower horsepower motor.

Compressible fluids expands caused by pressure drops (friction) and the velocity will increase. Therefore is the pressure drop along the pipe not constant. We set the pipe friction number as a constant and calculate it with the input-data….

Surface Material | Absolute Roughness Coefficient – k (mm) |
---|---|

Ordinary wood | 5 |

In simple terms, the mathematical constant 2.31 converts a unit of energy against gravity into a unit of force against any other area. This constant converts a foot of head of water into pressure: Head in feet of water divided by 2.31 equals pressure in psi, and pressure in psi times 2.31 equals head in feet.

Bernoulli’s principle states that as velocity increase pressure decreases. But higher the velocity, greater is the temperature and pressure must be high.