Venturimeter orientation: effect of inclination on indicated differential head A venturimeter is installed in an inclined position instead of perfectly horizontal. For the same discharge, how does its indicated differential head (and hence computed reading) change?

Introduction / Context:
Venturimeters measure discharge by relating the pressure difference between the inlet and the throat to the velocity change. Practitioners often wonder whether pipe inclination alters the indicated head and thus the computed flow rate.

Given Data / Assumptions:

• Proper pressure tappings at the inlet and throat.
• Same volumetric flow rate and fluid properties.
• Differential manometer (or transmitter) measures pressure difference between the two tapping points.

Concept / Approach:
Bernoulli between the two sections includes elevation terms. However, the instrument measures piezometric head difference that already accounts for elevation. For a given discharge, the velocity distribution at inlet and throat is the same regardless of the pipe’s overall inclination, so the measured differential head corresponding to velocity difference remains effectively unchanged (neglecting minor secondary effects).

Step-by-Step Solution:

Verification / Alternative check:
Manufacturers specify that a venturimeter can be mounted in any orientation; calibration coefficients remain valid.

Why Other Options Are Wrong:

• More/less reading: would imply orientation changes the inherent pressure-velocity relation, which it does not for the same Q.
• None of these: incorrect since “same reading” is standard guidance.

Common Pitfalls:
Confusing static head changes along an inclined run with the differential reading between two fixed stations; ignoring proper datum handling.

Final Answer:
same reading