How do you calculate valve torque?
Dynamic torque can be calculated from the formula Td = C (ΔP). Here, ΔP is the effective pressure drop across the valve at a given temperature and C is, once again, a constant.
What is Torque valve?
A torque-seated valve (e.g., gate valve) will use the torque switches to properly seat the valve at the required torque setting. There is often a torque switch electrical bypass in the opening direction so that more torque is available to break the valve out of its seat.
How do you read valve sizes?
The volume flow rate for liquids can be calculated by multiplying the fluid velocity times the flow area. Thus, Cv is numerically equal to the number of U.S. gallons of water at 60°F that will flow through the valve in one minute when the pressure differential across the valve is one pound per square inch.
What is Valve breakaway torque?
Valve breakaway torques are the highest torques expected, without accounting for resultant dynamic forces caused by flow through the valve. Seat Materials: The type of seats used in a ball valve significantly influence operating torque. This friction force is primarily a result of the seat material.
How do you reduce torque on a ball valve?
Valve torque is also a function of the media flowing through the valves. Abrasive media have a tendency to increase the amount of friction between ball and seats, whereas some light oils, which provide extra lubricity, can decrease the amount of torque required.
What is actuator safety factor?
Safety factor is a given multiple of the valve’s operating torques to ensure proper operation of the actuator. Many customers ask for a 25% safety factor so if a valve requires 100 in-lb torque to open, the actuator’s break torque would be sized at 125 in-lbs. Modulating service, also known as throttling service.
What is a good factor of safety?
General recommendations
| Applications | Factor of Safety – FOS – |
|---|---|
| For use with highly reliable materials where loading and environmental conditions are not severe and where weight is an important consideration | 1.3 – 1.5 |
| For use with reliable materials where loading and environmental conditions are not severe | 1.5 – 2 |
How do you size an actuator?
To size an actuator correctly, we need to understand: Minimum and maximum supply pressure….Understanding Minimum and Maximum Supply Pressure
- be capable of operating at the minimum supply pressure available.
- develop sufficient torque to overcome the valve torque throughout the complete stroke.
How do you calculate maximum allowable stem torque?
Valve torque calculation:
- Sm (Design stress intensity value) = 2/3*YS (ASME code Section II, Part D,Ed2010)
- ASME code Section VIII, Div2, Part AD-132.
- API6D /ISO 14313 (Design specification for Ball valves) Reference.
What is allowable torque?
Abstract. Maximum allowable stem torque/thrust (MAST) is defined as the maximum torque/thrust that can be applied to the valve train without risk of damage, as defined by the valve manufacturer/supplier.
How do you calculate mast?
MAST = yield shear stress * (radius of shaft)^3/ B, where B is obtained from the Petersan’s handbook.
What is BTO torque?
BTO = Break To Open Torque (Under rated differential pressure) RUN = Running Torque. ETC = End To Close Torque. ETO = End To Open Torque.
How do you calculate mast height?
Measure the stick, the distance from eye to stick, stick to mast, multply the stick length by the distance of the eye from the mast divided by the distance of the stick to your eye.
How is height of mast measured?
Mast height is almost always measured from the water. But to be sure you know the how high the top of your mast is from the water, measure the actual height of the mast from the deck to the top of the halyard (tape measure) and then add a foot to account for the sheeve typically being below the actual top of the mast.
How tall should mast be?
62 feet
How tall is a catboat mast?
From a distance, the large models, say 22 to 25 feet, seem as friendly as a Beetle, but up close the size of the spars and massive spread of sail may intimidate the faint of heart.
How tall is the mast on a 40 ft sailboat?
Specs
| Length Overall | 41’3″ | 12.57 m |
|---|---|---|
| Mast Height – From Waterline – Furling | 63’3″ | 19.28 m |
| Sail Area – Standard | 1,006 sq ft | 93.46 sq m |
| Sail Area – Furling | 910 sq ft | 84.54 sq m |
| Headroom | 6’6″ | 1.98 m |
How tall is a yacht mast?
Agreed, an 8m mast on a 7.5m boat isn’t uncommon. For example the Hunter 25 (which I have in the yard at the moment) is 7.57m long, 2.44m in beam, with a 6.15 LWL, draws 1.19m and it’s P dimension is 7.56m and it’s I dimension is 9.14. The mast height is about 8m.
What is the top of a ship’s mast called?
mainmast
Why is it called a mizzen mast?
The name of the third, aftermost, mast of a square-rigged sailing ship or of a three-masted schooner, or the small after mast of a ketch or a yawl (but see also jigger-mast). The word also possibly came from the Arabic misn meaning mast, and was associated with the lateen sail, also of Arabic origin.
How tall is the mast of a galleon?
120 ft.
Why is galleon so good?
Many European countries used galleons as merchant or supply ships in peace, and could quickly convert them to war ships in times of trouble. The Spanish used the vast amount of cargo space in the galleon to carry the New World treasure across the Atlantic. The galleon could withstand the rigors of ocean voyages.
How big were ships in the 1600s?
For more details see our historical page. Carracks for exploration like the Santa Maria or de Gama’s San Gabriel were small, about 90 tons; but merchant ships would average 250-500 tons with a crew of 40-80 and some war ships went up to 1000 tons.
Is a frigate bigger than a galleon?
The Frigate is a 6-Cannon, 2 Mast ship that is 2x bigger than the Sloop but smaller than the Galleon that can hold up to 3 people.
Which is more powerful frigate or destroyer?
The term “frigate” was readopted during the Second World War by the British Royal Navy to describe an anti-submarine escort vessel that was larger than a corvette, while smaller than a destroyer. Equal in size and capability to the American destroyer escort, frigates are usually less expensive to build and maintain.