Falling Weight Impact Tester for Thermoplastic Pipe

What is the Falling Weight Impact Tester for Thermoplastic Pipe?

A falling weight impact tester drops a defined mass and striker onto a pipe or fitting specimen to assess resistance to external damage. It is required by pipe product standards for water, gas and drainage applications and is normally performed at low temperature.

Overview

A guide tube or frame releases a striker of defined mass and geometry from a set height onto a pipe section supported on a flat base, and the specimen is inspected for cracking, splitting or wall penetration. Impact energy is set by mass and drop height, and the striker head is selected to represent the damage of interest, for example a hemispherical or a chisel-shaped tup. Because pipe toughness falls sharply at low temperature, specimens are conditioned in a bath, often at 0 °C, and transferred within a short defined time. The mass, fall height, striker geometry, support arrangement and conditioning temperature are all specified by the product standard, and both real impact and staircase procedures are used, depending on whether a pass or fail decision or a 50% failure energy is required.

How does it work?

Impact tests apply a defined energy in a very short time, so the material responds in a brittle or semi-brittle manner that differs from slow tensile behaviour. Pendulum instruments release a weighted hammer from a fixed angle; the hammer strikes a supported or cantilevered specimen and the energy absorbed is calculated from the difference between release and follow-through angles, or measured directly by an encoder. Instrumented hammers add a strain-gauge striker that records force against time, so crack initiation and propagation energies can be separated. Drop weight and dart methods use a falling mass: a dart striking a clamped film gives the energy for 50% failure, while a tup striking a pipe section assesses resistance to external damage. Specimen geometry, notch radius, support span and conditioning temperature all control the result.

What are the key features?

• Drop heights from 0.5 to 2.5 m
• Interchangeable strikers including hemispherical and chisel types
• Pipe supports and V-blocks for different diameters
• Motorised mass lifting and release
• Low-temperature conditioning bath
• Interlocked enclosure for operator safety

What are the technical specifications?

A typical falling weight impact tester for thermoplastic pipe configuration offers drop height of 0.5–2.5 m adjustable, falling mass of 5–20 kg with additional weights, impact energy of Up to about 500 J, striker geometry of Hemispherical, chisel or per product standard, specimen length of 200 mm nominal or three diameters minimum and nominal diameters of 16–630 mm with supports. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Falling Weight Impact Tester for Thermoplastic Pipe is used in water and gas pipe impact resistance testing, drainage and sewer pipe product certification, incoming verification of pipe deliveries and fitting and joint impact assessment. Across the wider Impact Analysis class, laboratories also deploy it for impact strength qualification of moulding grades, notch sensitivity comparison between formulations and low-temperature toughness testing.

Which standards and certifications apply?

Relevant standards and methods include ISO 179-1, ISO 180, ISO 6603-2, ISO 8256, ASTM D256, ASTM D6110, ASTM D1709, ASTM D2444 and IEC 61010-1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Cut specimens with the notch in the specified orientation, because anisotropy from moulding flow changes the result substantially; use a motorised notch cutter and verify the notch radius with a profile gauge. Condition specimens at 23 °C and 50% relative humidity, or in a bath at the test temperature when low-temperature toughness is measured, and transfer them to the machine quickly. Verify the pendulum by releasing it without a specimen, confirm that friction losses stay within the standard limit, and check the blade and supports for wear or damage. Report the specimen type, notch geometry, hammer energy and observed failure mode together with the numerical result.

How do I select the right Falling Weight Impact Tester for Thermoplastic Pipe?

Specify this equipment when your pipe product standard requires a falling weight test, and confirm the striker geometry and conditioning temperature it names, because impact results are highly specific to both. Check the diameter range and support fittings against the pipes you handle, and ensure the transfer time from the bath to the machine can be met.

How does it compare with other Impact Analysis variants?

Select the method named in your material or product specification, because results are not interchangeable between geometries. Izod suits rigid moulding materials and is common in resin specifications, while Charpy is preferred for plate, sheet and weld evaluation and is more widely used in Europe. Instrumented hammers are chosen when the failure mode itself must be studied rather than only the absorbed energy. Falling dart testing applies to films and thin sheets where a pendulum cannot hold the specimen, and falling weight testing applies to pipes, fittings and thick sections. For any of these, specify the energy range, specimen conditioning options, notch-cutting equipment and whether low-temperature conditioning is required.