Technical Features: Series 54 & 55

 

 
STANDARD FEATURES TYPE 54 TYPE 55 COMMENTS
Size range 1 1/2” FB up to 6” RB 6" up to 60"
Pressure ANSI 150 thru 2500 e API 6A 1ANSI 150 thru 2500 e API 6A
Three piece split body YES YES
Anti-static device YES YES
Self relieving seats YES NO 55 option (no extra cost)
Double Piston Effect seats NO YES 54 option (no extra cost)
Lubricated stem YES YES
Lubricated seat NO YES 54 option*
Double block and bleed YES YES
Metal to metal seats YES* YES*
Trunnion mounted ball YES YES
Full or Reduced bore YES YES
Bi-directional YES YES
Minimum thickness ASME B16.34 YES YES
RF or RTJ flanges to ASME B16.5 YES YES Other flange design*
BW (butt-weld) ends to ASME B16.25 YES YES Other code for BW design*
Bore and end-to-end YES YES Dimensions other than API 6D*
Manufacture in accordance with API spec. 6D YES YES ASME B 16.34 design available on request*
Materials certification to EN10204 type 3.1.B for pressure containing parts, ball, stem and seats YES YES Type 3.1.C materials certification level*
Fire safe design to API 6FA (BS 6755 Pt.2) YES YES Other fire safe code (e.g. API 607)*
Bolting ASME VIII div. I YES YES ASME 16.34 available*
Operation by lever, gear w/ handwheel or actuator YES YES
Ease of maintenance Requires valve removal from line in order to perform maintenance
* available with extra cost
 
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Trunnion mounted ball valve

When the ball is in fully closed position, two trunnions absorb the side thrust generated by line pressures, preventing excess friction between ball and seats. With this system, even at full rated working pressure, operating torque stays low. Therefore a generous sizing of trunnions is essential to the life and operability of the valve. The spherical surface is machined and ground to close tolerance. To reduce torque and minimize wear, the ball is then electroless nickel plated and polished to mirror finish. For special applications the ball may be hardfaced with T.C.C. (Tungsten carbide coating) to improve resistance to wear and prevent scratching caused by hard particles.

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Emergency stem and seat sealant injection

In case of emergency, when sealing materials (seat sealing and stem o-ring) are damaged or decomposed by fire or other accidental causes, a sealant injection into fittings on both stem and seat prevents leakage until the primary seal is restored. For Type 54 ball valves the seat sealant injection is an optional feature available with an extra cost.. However, the material between ball and seat is a thermoplastic seal, thus no further injection is necessary. Self lubricated, low friction materials are used for stem bearings, stem seals and body seats. Low friction materials, e.g. nylon, are used for seat inserts. Stem bearings and self-lubricating seals give predictable operating torque for the life of the valve.

 

Stem

The stem is made separately from the ball. It is blow-out proof, obtained with an integral collar in the bottom of the stem.

 

Stem SEAL

Sealing system consists of three sealing points: two static o-rings seal the stem, plus a third graphite seal is retained by the adaptor flange. This ultimate seal can be replaced when the valve is in line and in the closed position.

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SEAT DESIGN

 Type 54 ball valve: plastic polymer insert for seat sealing, spring energised. Type 55 ball valve: primary metal-to-metal seal and secondary synthetic o-ring seal, spring energised.

 

BODY DESIGN

 VALVITALIA trunnion mounted valves have a compact and streamlined body for maximum strength and minimum weight. Uniform fine grain  structure and toughness is assured by using forged steel materials.

 
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DOUBLE BARRIER ON BODY JOINTS

VALVITALIA valve design assures double barriers for all leakpaths. In this way, when one fails, the other seals.


Fire safe design and test

 Fire safe is a standard design on all Valvitalia ball valves. Two o-rings and gland gasket prevent leakpaths from the valve stem area, o-rings and body gasket prevent leakage through the valve body. If fire deteriorates the o-ring, the gland gasket, body gasket and the stem firesafe packing prevents fluid or gas leakage. Valvitalia soft seat ball valve fire safe test (shown in the image) was witnessed and certified according to API 607 - API 6 FA - BS 6755


ANTI STatic device

This device is a standard feature on VALVITALIA ball valves. A coil spring thrusts a small sphere, providing grounded continuity between stem and other metallic components of valve (ball and body) in order to avoid sparks during stem rotation when opening and closing the valve and preventing problems in case of use with flammable fluids and gas.


body vent and drain

The drain and vent plug on the valve body enables verification of the seat ring's integrity. A bleed valve may replace the drain plug.


Double block and bleed

The drain and vent plug on the valve body enables verification of the seat ring's integrity. A bleed valve may replace the drain plug.


Double piston effect (55-Standard, 54-Option)

VALVITALIA valve design features two seating surfaces between which the cavity can be vented through a bleed connection thus confirming the tight sealing of the valve, in both the closed position and open position, when pressure is applied to either side or both sides of the valve.

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Self relieving seat 

In a self relieving condition, excessive internal body pressure is automatically relieved both in both upstream and downstream directions by forcing the seats away from the closure element.

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