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HIGHER INTEGRITY 
By selecting valve with a forged body the user automatically increases the safety and integrity of their plant and process equipment. It has long been known that forged valve are tougher, more resistant to impact, withstand higher induced pipe stresses, and are more structurally superior to equivalent castings.
MAINTAINABILITY
Most all small-bore pressure seal bonnets are equipped with large-diameter threaded mechanisms to engage the bonnet and pressure seal gasket.
It is very well known in industry that large-diameter threads are extremely troublesome during maintenance, especially in high-temperature applications where over time oxides develop in the threads rendering them almost impossible to separate. The new SB design of forged pressure seal is the “small-bore valve with big bore advantages”. This innovation incorporates features normally reserved for large bore pressure seals into this neat yet accessible package. Its accessible and very maintenance-friendly. PK has adapted the conventional large-diameter valve bonnet draw bolt mechanism into this small-bore design. The innovation made possible by reversing the conventional draw bolts mechanism into a jacking bolt design.
INTERNALLY MACHINED BODY GUIDES
The SB Series Body has internally machined Obturator guides that are more accurate and less problematic than the conventional welded guides.
Welded guides can break due to stress and vibration or even corrosion and could result in parts ending up in the process. Guide failure can also result in the valve jamming.
Precision machined guides result in less obturator vibration. Poor Quality guiding causes damage to the seating surfaces. SB Series innovation is inaccurate machining, resulting in the obturator being held steady and in the desired position.
SELF-CENTERING ASSEMBLY
The Body to Yoke mating surface is equipped with a Centering Shoulder that serves as a guide to the Jacking Ring.
The shoulder captures the Jacking Ring thus preventing misalignment during assembly and retains the Ring in position while the jacking bolts apply the initial force to the bonnet and pressure seal gasket
ACTUATOR 
Dual thrust bearings reduce friction and minimize actuation hysteresis. The use of Ball Bearing reduces friction and makes for smooth handwheel operation. The Yoke Cap is tack welded to prevent accidental loosening
ACTUATOR MOUNTING
Because Yoke is robust cast steel it can accommodate actuation. When ordered the valve yoke can be supplied complete with actuator mounting flange. The flange can be pre-drilled to match the customer drawings to facilitate actuator ease of actuator installation
THE PRESSURE-SEAL GASKET
The SB series is offered with two styles of pressure seal gasket. For most applications and unless specified by the purchaser the SB serious will be provided with an Inconel Graphite composite gasket. Alternately and for the more severe applications a silver-plated soft iron gasket can be provided.
The pressure seal jacking mechanism will be fully engaged during factory Hydro test and the seal integrity proven. Should it become necessary during the installation to disassemble the valve, then the pressure seal gasket should be replaced. Pressure seal gaskets are not reusable.
THE SB SERIES COMES STANDARD WITH SET OF DIE-FORMED GRAPHITE V-RINGS RMED GRAPHITE V-RINGS
PILLAR FLEXIBLE GRAPHITE PACKINGS
BACKSEAT
The Backseat is accomplished by a hard-face weld overlay in Stellite #6 directly onto the bonnet which is then machined into a reciprocal cone to match the stem. Backseats should not be used for packing replacement while under pressure. This practice is dangerous and can result in serious injury.
It is also recommended that valve are not left in the backseat position permanently as the packing may dryout and deteriorate. It is better practice to open the valve fully to the backseat then rotate the hand-wheel one turn towards the closed position.
EASE OF MAINTENANCE
The SB Series design considered all aspects of the valve including maintainability. One of the key objectives in the design was to make a valve that provided ease of access to all bolting required by maintenance. The three bolting functions Gland, Jacking and Yoke within the yoke arch are layered and oriented in such a way that they provide an uncluttered ease of access.
The Jacking Bolts intentionally protrude above the Bonnet Clamp in order to provide access, this also mitigates any interference with the yoke flange bolting.
FORGINGS ARE STRONGER
Forgings surpass casting in predictable strength properties, producing superior strength that is assured, and repeatable from part to part. The grain in castings is random and cannot obtain the strengthening effects of hot and cold working. In the forging process, controlled deformation (usually at elevated temperatures) results in greater metallurgical soundness and improved mechanical properties of the material.
In most cases, forging stock has been pre-worked to remove porosity resulting from the solidification process. This produces directional alignment (or “grain flow”) for important directional properties in strength, ductility, and resistance to impact and fatigue.
These properties are deliberately oriented in directions requiring maximum strength. Working the material achieves recrystallization and grain refinement that yields the maximum strength potential of the material with the minimum property variation, piece to piece. Properly developed grain flow in forgings closely follows the outline of the component. In contrast, bar stock and plate have unidirectional grain flow;
FREE FORGING GATE VALVE
FORGING REFINES DEFECTS FROM CAST INGOTS OR CONTINUOUS CAST BAR.
A casting has neither grain flow nor directional strength nor can the process prevent formation of certain metallurgical defects. Pre-working forge stock produces a grain flow oriented in directions requiring maximum strength. Dendritic structures, alloy segregation, and like imperfections are refined in forging.
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