What the Software Checks

Once a model has been selected and positioned, Pihasa Assistant runs a series of verifications. This article lists them, says what each protects against, and — importantly — sets out what they do not cover.

The checks

Travel limits

Both the operating and the installed position must fall inside the model’s travel range. Optionally, both must also fall inside the recommended range, which is the inner band of the stroke.

Protects against: a spring bottoming out or topping out in service, which turns it into a rigid restraint.

Travel reserves

If you have defined reserves, the positions must respect them. If you have not, the software applies default margins.

Protects against: a support with no room to absorb the difference between the calculated and the actual movement.

Variability

For variable springs, the load change over the travel must stay within the allowed limit — set per project, per support, or defaulted.

Protects against: load being transferred to the piping system and adjacent supports in quantities the stress analysis did not anticipate.

Hydrostatic test load

The load during the pressure test is compared against the capacity of the load-bearing parts, principally the threaded rod.

Protects against: a support that is unfit to handle the extraordinary loads that happen during the test, when the line is full of water.

Material quality against temperature

The selected quality must be permitted at the operating temperature.

Protects against: a material used outside its service range.

Load capacity after temperature correction

The corrected design load must stay within the component’s tabulated capacity.

Protects against: selecting on nominal capacity and overlooking the reduction at temperature.

Lateral and axial load limits

For clamp bases, guides and U-bolts, the horizontal loads must stay within a fraction of the vertical load. The fraction depends on the component series and the pipe diameter.

Protects against: a base designed for vertical load being asked to resist horizontal forces it was not proportioned for.

Note that exceeding the lateral limit does not stop the calculation. The software applies a reinforcement, which shows up as an increased weight relative to the catalogue value.

Vertical deviation angle

For hanging supports, the angle the hanger makes with the vertical when the pipe displaces horizontally.

Protects against: a hanger swinging far enough out of plumb to introduce horizontal load components the design did not account for. See Vertical deviation angle.

Minimum distance between axes

For double supports, the two load-bearing elements need physical clearance. The software calculates the minimum centre distance from the pipe diameter, insulation and component dimensions.

Protects against: a double support that cannot be assembled.

Rod capacity

The rod size follows from the load, and the load must not exceed the capacity of that size.

Protects against: an undersized hanger rod.

Assembly coherence

A set of internal consistency checks: incompatible parts in the same assembly, rod lengths incompatible with the chosen metric, sliding plates incompatible with the clamp base, duplicate support tags within a folder.

Protects against: an assembly that cannot be built as drawn.

What is not checked at all

• Stress in any pipeline component. The software compares loads against tabulated allowables. It does not compute stresses.
• The loads themselves. They come from your analysis.
• The movements. Same.
• The suitability of the support type. Nothing prevents you specifying a variable spring where a constant is needed, provided the numbers happen to pass.
• Anything about the pipe. Wall thickness, stress, supports spacing, allowable spans — none of it.

Warnings are not refusals

The most important thing to understand about the checking stage: the software proposes a model even when the checks fail.

If no candidate satisfies every criterion, it returns the best available anyway, with warnings. This is deliberate — it is more useful to show the closest option and flag the problem than to return nothing — but it means a completed datasheet is not by itself evidence that the support is acceptable.

Read the warnings. A support with warnings is a support that needs a decision.