advantage ball vs globe
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DELATITE BALL VALVE VS GLOBE VALVE
GLOBE VALVE
1: Plug and Seats are in the Flow Path

2: Plug must be torqued onto the Seat

3: If the Valve is Open Running Hot Fluid and is then closed, the fluid can cool down. This cooling will cause the stem to shrink and therefore reducing the torque on the seat, which creates real potential for leakage.

If the pressure is high enough as is the case in many power station applications this leakage will cause wire drawing and valve leakage which if left un checked could cause major damage to the valve and plant.

4: Tortuous Flow Path results in low valve capacity.

5: Rising stem moves vertically through packing.

6: Plug and seat are generally made of softer material ie: Alloy 6

7: Seat is integral part of the valve body. Damage the seat and you damage the body.

DELATITE BALL VALVE
1: Compact ¼" turn Design

2: Seat are out of the Flow Path

3: Floating Ball Utilizes Line Pressure to assist Sealing

4: Quarter Turn: When valve is closed the cooling of the fluid in the line will not affect shutoff

5: Bellville Spring loads the ball into the seat

6: Shaft Rotates in the packing reducing the chance of stem leakage.

7: Streamline flowpath give higher CV values.

8: Hard materials (Rc 73-74) on the ball and seats are mate lapped.

WHAT ALL THIS MEANS TO THE CUSTOMER
1/5 The Delatite Ball Valve has quarter turn operation. This operation of the valve enhances the packing life as the stem motion through the packing is much less than that of rising stems which are used by globe valves.

The stem of the Delatite Ball Valve does not change its vertical position.

The mounting bracket of the Delatite Ball Valve is precision machined, If actuators are fitted this lessons the chance of misalignment which could force the stem to one side which
would reduce packing life.

The valve stem is also supported in the mounting bracket.

2: The rotating action of the Delatite Ball Valve means that no fluid needs to be displaced during operation of the valve.

The ball has a wiping or cleaning action on the seat every time the valve is actuated. This reduces the risk of foreign material being dragged onto the seat which could cause premature valve failure.

The Globe Style Valve must move process fluid to operate. If foreign material is in the flow stream this material may be caught between the plug and seat therefore may cause seat leakage due to an inability to form a tight shutoff. Foreign material may damage the seating area of the globe valve by causing mechanical damage as the globe valve closes and foreign material is caught between the plug and seat.

3: The Seats and Sealing area of the Delatite Ball Valve are out of the flow path.

This protects the seats from damage by foreign material in the fluid thus dramatically increasing the life of the valve.

The seats and plug of the globe valve are exposed to the process fluid at all times while the valve is being operated. This even occurs when the valve is fully open.

4: The Delatite Valve has a smooth unobstructed flow path. This increases valve capacity per bore size also reducing velocity turbulence and wear.

The Globe Style Valve has a torturous flow path which create turbulent flow high velocity flow which reduces capacity. This turbulent high velocity flow can also damage sealing areas of the Globe Valve plug and seat.

6: All sealing surfaces of the Delatite Ball Valves are coated with Carbide LLK 1906

This carbide has been specially developed for Delatite Valves to resist abrasion and cutting while maintaining a tight shutoff in both High and Low temperature applications. This carbide has a hardness of approx 73 – 74 Rc.

The ball and seats are mate lapped to give a tight shutoff to

MSS-SP-61-2003 for isolation valves.

The globe style valve generally use stainless steel trim with alloy 6 coating. Alloy 6 has nowhere near the hardness off LLK 1906 (36-42 Rc vs 73-74 Rc) this difference leads to premature valve failure due to cutting or wire drawing. Alloy 6 losses strength under high temperature conditions.

The seats in the Delatite Ball Valve are replaceable and the valve can be readily repaired.

The seat of the Globe Valve is normally integral therefore if erosion or wire drawing occurs to the seat you are actually damaging the valve body.

This can lead to the expense of body replacement and if let go long enough the globe valve could experience an uncontrolled catastrophic body failure which could damage other equipment but worst of all could injure someone in the plant.

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