A facility operator needs to open a large industrial gate valve to allow water flow. The v… — Armed Services Vocational Aptitude Battery (ASVAB)

A facility operator needs to open a large industrial gate valve to allow water flow. The valve's stem features a standard right-hand thread with $5$ threads per inch (TPI). The valve is currently fully closed. To allow maximum water flow, the internal gate must be lifted exactly $3\text{ inches}$ . What action must the operator take to fully open the valve?

Turn the handwheel counterclockwise for $15\text{ full revolutions}$ .Cevap
B
Turn the handwheel clockwise for $15\text{ full revolutions}$ .
C
Turn the handwheel counterclockwise for $0.6\text{ of a revolution}$ .
D
Turn the handwheel clockwise for $0.6\text{ of a revolution}$ .

Cevap

Turn the handwheel counterclockwise for

15\text{ full revolutions}

For a standard right-hand thread, counterclockwise rotation is required to withdraw or lift the mechanism. Since the stem has 5 threads per inch, it takes 5 full revolutions to move the gate 1 inch. To move the gate 3 inches, the operator must turn the handwheel

3 \times 5 = 15\text{ full revolutions}

Adım Adım Çözüm

Determine the required direction of rotation.

Counterclockwise rotation.

Standard right-hand threads advance (close or move away) when turned clockwise. To lift the gate (open or move toward the operator), the handwheel must be turned counterclockwise.

Determine the linear distance traveled per revolution (pitch).

Pitch =

1 / 5\text{ inch}

per revolution.

TPI (threads per inch) tells us that

5\text{ threads}

fit in

1\text{ inch}

. The distance of a single thread (one revolution) is the inverse of the TPI.

Calculate the total revolutions needed to travel the target distance.

3\text{ inches} \times 5\text{ revolutions/inch} = 15\text{ revolutions}

Multiplying the total required distance by the number of threads per inch gives the total number of revolutions required.

Anahtar Kavram

Screw Pitch, TPI, and Thread Direction

Tahmini Süre:1m 0s

Soru

Cevap

Adım Adım Çözüm

Anahtar Kavram

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