Object: To determine the coefficient of resistance due to a slanted seat valve.

Apparatus:

fluid friction apparatus; hydraulic bench, slanted seat valve, and stopwatch.

Fig. Fluid friction apparatus

Theory:

The minor loss due to a slanted seat valve is a function of the velocity head and is written as

hl = Kssv. 𝑣2 / 2𝑔 (1)

where

hl = loss of head due to Elbow

V = velocity of flow = Q/A

Kssv = resistance coefficient of slanted seat valve

Procedure:

1. Fill the tank of the hydraulic bench with clean water.
2. Connect the fluid friction apparatus with the hydraulics bench.
3. Open the valve(s) that allow flow to the section under consideration and close all the irrelevant valves of the pipe friction apparatus.
4. Connect the two ends of the tubes to the pressure-tapping nipples b/w the interchangeable section and the manometer.
5. Slightly open the flow control valve on the hydraulic bench.
6. Remove air bubbles from the tubes by opening the vent valve and drain valves of the differential manometer.
7. Read the heads in the monometers corresponding to the pressure along the entry and exit of the slanted seat valve.
8. Collect water in the volumetric measuring section of the hydraulic bench. Read the volume collected as well as the time taken to collect that volume of water.
9. Open the flow control valve at the hydraulic bench slightly more to take new readings.
10. Repeat steps 7 and 8 to observe new readings.
11. Carry out computations as per the below table -1 and compare the range of Kssv for a slanted seat valve with that given in the literature, i.e. Kssv 1.5-2.0
12. In order to investigate the throttling behavior of the slanted seat valve, carry out the computations as per below table-2 and plot the graph b/w discharge and rate of opening valve.

Observations and Calculations:

Table-1

Table-2

Graph:

Comments: