:: DESIGN/Assembly Features::
Taper-Lok® pressure-energized connectors are engineered to provide the safest seal of any bolted connection. Available in nominal pipe sizes from 1/2" to 83", pressures to 40,000 psi, and temperatures and cryogenic services ranging from –350 to 1600º F. Taper-Lok® connectors provide unequaled design flexibility.
The converging 10° & 20° angle wedge creates a mechanical advantage and requires a smaller bolt load to seat the seal ring while achieving a higher resultant load. In addition, smaller bolts are required and the overall flange size is decreased, thereby enhancing a compact flange design. Surfaces of the Taper-Lok® seal ring are nearly parallel to their axial centerline. This converging design provides reduced end loads, thereby allowing the use of smaller bolting, bolt loads and bolt circles. This geometry is what gives all Taper-Lok flanges a self-energizing and pressure-energizing seal. The seal's pressure-energized characteristics, coupled with its lighter bolt-load requirements, result in a more compact design permitting significant space and weight savings. Taper-Lok®'s design differs markedly from the radial type seals and gaskets commonly used in conventional components, making Taper-Lok® connectors 60-70% lighter that their conventional flange counterparts. The Taper-Lok compact flange offers a significant overall size weight savings as compared to ANSI or API flanges, in addition to ease in assembly and maintenance.
One of the benefits of the Taper-Lok seal ring is the self-energizing effect. As the bolts are tightened to the recommended bolt preload, the seal ring is placed in hoop compression and slides into the female flange. This causes the seal ring to compress tangentially as the diameter decreases. A restoring force exists in the seal ring, much like that of a compressed spring or bevel washer. The reaction of this compressive force, trying to push the seal ring out of the female seal pocket and tighter into the converging tapered surfaces of the male nose and female pocket, is what creates the self-energized seal.
Pressure / Self Energized
The working pressure of the system benefits the sealing integrity of the Taper-Lok seal. Internal pressure acting on the bottom of the seal ring attempts to force the fully confined seal ring out, wedging it further into place against the converging male and female seal surfaces forming an even tighter seal as pressure increases or bolts relax. Because of this wedging action, the higher the working pressure, the tighter the seal.
Lower Torque Requirements
Connections leak due to a variety of reasons right from improper bolt preloads to gasket relaxation. There are approximately 75 factors that affect the tension in a bolt when torque is applied. Due to the self-energizing affect, Taper-Lok connections do not have to consider gasket factor or design seating stress, in accordance with ASME Section VIII Division 1 and 2, Mandatory Appendix 2, which enables a significantly lower bolt pre-load needed to overcome the hydrostatic end load. Smaller bolts and less bolt load translate to ease in maintenance and assembly over a standard connection. Because of the self-energized and pressure energized characteristics of the Taper-Lok connection, the allowance for the margin of area is much larger and more forgiving during the installation as compared to standard connections.
Taper-Lok connections are of suitable extra length for 100% tensioning with Integra or Hydratight Sea Serpent® subsea bolt tensioner systems where all nuts, or just half, are provided with Tommy bar holes as a standard.
The ability to impart a full seal with substantially smaller bolt loads allows most Taper-Lok® components to be installed with conventional hand tools and impact wrenches. The elimination of special bolt-tensioning equipment means time and cost savings during installation.
Self Aligning, Visible Seal
The tapered angle design is self-aligning by the nature of the components, and offers a significant installation benefit. The male and female geometry of the mating components promotes a self-aligning action during assembly and has virtually eliminated seal ring positioning problems. The female Taper-Lok component holds the tapered seal ring in place for easier and quicker bolt up.
In addition, the seal ring is always externally visible, even when assembled, allowing inspection for proper installation and seal integrity at any time.
The tapered design of the sealing surfaces offers several other practical advantages. Taper-Lok® connectors are engineered to accept up to 2-degrees axial pipe misalignment and still deliver a full high integrity seal. The flange faces do not need to be exactly parallel prior to installing the bolts with a Taper-Lok connection. The frequent warpage of heavy wall pipe, a result of high heat generated during welding, makes this an important advantage of Taper-Lok®. Another installation benefit is the self-aligning nature of the components. The tapered male and female geometry of the mating components promotes a self-aligning action during assembly. Taper-Lok has engineered products that offer various solutions for offset and misaligned pipe.
The Taper-Lok® design has virtually eliminated seal ring positioning problems associated with other metal seal design. The male Taper-Lok® component holds the tapered sealing in place for easier and quicker bolt up. In addition, the seal ring is always visible, even when assembled, allowing inspection for proper installation.
The Taper-Lok flange design withstands high external loads during service. Typical connections that crush, plastically deform, and yield the gasket material require high pre bolt-loads to be applied in order to create a seal in the connection. This yielded gasket does not offer flexibility to take up in the dynamic loading and cycles experienced by the connection, resulting in leaks. Since the Taper-Lok seal is seated into place and not crushed, the material is not yielded and lower bolt pre-load allow for safe stress growth in the bolts during applications with induced external loads.
Taper-Lok connections are very robust and forgiving along the sealing surfaces. Due to the wide sealing area, the Taper-Lok connection offers much more sealing area to maintain a seal should a surface become scratched or damaged. Should sealing surfaces become scratched in the field, it is typical to buff out the damage with an emory cloth.
Resistance to Corrosion
Taper-Lok seal rings are loaded strictly in compression and offer very low susceptibility to a connection usually plagued by “Stress Corrosion Cracking”. Even in a highly corrosive environment, the sealing surface of a Taper-Lok Seal ring is longer than the wall thickness of the pipe, essentially the pipe wall will allow penetration before the entire length of our sealing surface is sacrificed.