# How Do You Determine Pipeline Pressure with a Faulty Manometer?

• GOPgabe
In summary, the conversation discusses using an open-ended mercury manometer to determine the pressure in a pipeline supplying feed gas to a reactor. The calibration markings for the manometer are faded, requiring improvisation. The conversation then discusses using a bourdon gauge to measure pressure in the pipeline and the corresponding heights of mercury in the manometer. The conversation concludes with a discussion on the gauge pressure in the gas pipeline when the gas flow is turned back on.
GOPgabe

## Homework Statement

You are given an open-ended mercury manometer and asked to determine the
pressure in a pipeline that supplies feed gas to a reactor. However, when you connect the
manometer to the pipeline, you notice that the calibration markings in the leg that
connects to the pipeline are faded and not readable. You need to improvise.

(a) With the manometer still connected, you turn off the gas flow and use a bourdon
gauge to measure the pressure in the pipeline at several positions. Would you

(b) With no gas flowing, the bourdon gauge reading is 6.2 psi and the mercury level
in the open leg is 800 mm above the base of the manometer. What should be the
corresponding height of mercury in the manometer leg connected to the pipe line?

(c) Now you turn back the gas flow and observe that the manometer level in the open
leg increases by 30 mm. What is the gauge pressure in the gas pipe line?

## Homework Equations

Pabs = Pgauge + Patm

## The Attempt at a Solution

a.) My answer would be no. There's no fluid in the pipe and so there won't be a change in pressure along the path of the pipe.

b.) My first question is: why is there a pressure in the pipe? There's nothing colliding against the walls. That aside, 6.2 psi = 321 mmHg, that means it will displace 321 mmHg. This will result in a height of 1121 mmHg.

c. 30 mmHg = .5801 psi, the total gauge pressure would just be 6.7801, correct?

I feel as if I'm missing some important concepts here. I just don't have an intuitive grasp of the concept of pressure despite it simply being the ratio of a force to an area.

b) Unless the pipe is evacuated, there is always some pressure inside. Just because there is no flow, it does not follow that there is no pressure.

## What is fluid flow through a pipe?

Fluid flow through a pipe is the movement of a liquid or gas through a closed system of pipes. This can occur in various systems such as plumbing, industrial pipelines, and hydraulic systems.

## What factors affect fluid flow through a pipe?

There are several factors that can affect fluid flow through a pipe, including the size and shape of the pipe, the viscosity of the fluid, the pressure and velocity of the fluid, and the presence of any obstacles or obstructions in the pipe.

## How is fluid flow through a pipe measured?

Fluid flow through a pipe is typically measured using a flow meter, which measures the volume or mass of fluid passing through the pipe per unit time. This information can then be used to calculate the flow rate and other important parameters.

## What is the difference between laminar and turbulent flow in a pipe?

Laminar flow occurs when fluid moves in a smooth and orderly manner through a pipe, with layers of fluid sliding past each other without mixing. Turbulent flow, on the other hand, is characterized by chaotic and irregular motion of fluid particles, often caused by high velocities or obstructions in the pipe.

## How can fluid flow through a pipe be controlled?

Fluid flow through a pipe can be controlled by adjusting the pressure, flow rate, or velocity of the fluid. This can be achieved through the use of valves, pumps, or other flow control devices. The design and layout of the pipe system can also play a role in controlling fluid flow.

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