Glossary

Terms as they are used in Pihasa Assistant and throughout this knowledge base. Where a term appears as a field on the support datasheet, the field name is given in bold.

Admissible travel — the full physical stroke of a spring support, from one end stop to the other. Compare recommended travel.

Assembly — the complete set of parts making up one support, from the structural attachment to the pipe attachment. Quantity of Assemblies states how many identical units are required for one support tag.

Axial — along the axis of the pipe. Applies to axial movement and axial load.

Clamp base — a support that carries the pipe from below on a shoe gripped to the pipe with clamps, rather than hanging it. Also covers guides and U-bolts in the software.

Cold load — the load a support carries in installed, cold condition. Field: Preset Load (Cold Load). For variable springs it can be entered instead of the hot load by unlocking it with the lock icon.

Combined extension — for snubbers, the extension resulting from vertical and axial movements taken together over the installation length. Not the arithmetic sum of the two movements.

Constant spring support — a support that carries the same load throughout its travel. Variability is zero by construction. Used where vertical movement is too large for a variable spring.

Custom diameter — a pipe size entered as a value rather than chosen from the standard list. Catalogue data is taken from the nearest standard equivalent.

Deviation angle — the angle a hanging support makes with the vertical when the pipe displaces horizontally. See Vertical deviation angle.

Double support — a support carrying the pipe on two load-bearing elements. The Load Calculations field states whether the entered load is for the assembly or for each element.

Dynamic clamp — the pipe attachment used with struts and snubbers. Available in three options with different temperature and material ranges.

Estimated weight — the catalogue weight of a part as standard. Compare real weight.

Hot load — the load a support carries in operating condition. Field: Operational Load (Hot Load). The primary input for selection.

Hydrotest load — the load during the pressure test, with the line full of water. Field: Hydrotest Load. Used for checking only; it never selects or sizes anything.

Insulation thickness — field: Insulation Thickness. Affects geometry — take-outs and attachment heights — but not load capacity.

Installation height — the vertical distance between the structure and pipe elevations. Derived from the Elevations fields.

Lateral — perpendicular to the pipe axis, horizontally. Applies to lateral movement and lateral load.

Operating temperature — field: Operational Temperature. If left blank, a default is assigned based on the material quality.

Pipe attachment quality — field: Pipe Attachment Quality. The material of the component that contacts the pipe, not of the pipe itself.

Real weight — the weight of a part corrected for the actual dimensions of this assembly. Compare estimated weight.

Recommended travel — the inner band of a spring’s stroke, excluding a margin at each end. Working within it leaves room to absorb the difference between calculated and actual movement.

Rigid hanger — a support that carries load without accommodating vertical movement. Appropriate only where the vertical thermal displacement is negligible.

Sacrifice plate — a wear plate fitted to guide clamps and U-bolts.

Sliding plate — a low-friction plate between the pipe support and its bearing surface, in PTFE or graphite-bronze, flat or spherical.

Snubber — a hydraulic shock arrestor. Allows slow thermal movement and resists rapid dynamic movement.

Spring rate — the load change per millimetre of travel, in kg/mm or N/mm. The stiffness of the spring. Lower rate means lower variability for the same movement.

Strut — a rigid link resisting load along its axis, used for horizontal restraint.

Support tag — the unique identifier of a support within a project. Field: Support Tag. Must be unique within its folder.

Take-out — the dimension a part contributes to the overall length of the assembly. The Takeout List tab shows the breakdown.

Travel reserve — a margin kept clear at the end of a spring’s stroke. Fields: Travel Reserves Up and Travel Reserves Down. On constant supports, reserves enter the sizing directly.

Trapeze — a beam spanning between two structural points, from which the support hangs.

Trunnion — in this context, an anti-rotation trunnion on a clamp base. Its presence removes the lateral load check.

Turnbuckle — an adjustable link in a rigid hanger assembly. Added automatically above a threshold rod length.

Variability — the change in load between cold and hot conditions, as a percentage of the hot load. Field: Max Allowed Variability sets the limit. See Hot load, cold load and variability.

Variable spring support — a support carrying the pipe on a coil spring, where the load varies with vertical travel. Four series are available, trading travel range against stiffness.

Vertical movement — the thermal displacement along the vertical axis. The only movement whose sign the software uses: positive means the pipe rises when hot.