Precision gauging for pumps & valves.
Pumps and valves combine two kinds of features that need checking: the threaded ports and fasteners that hold the assembly together and seal it, and the plain bores and shafts that the moving parts run in.
Threaded ports and fasteners
Pressure-tight ports commonly use a taper pipe thread, NPT to ANSI/ASME B1.20.1 or an ISO 7-R / BSPT / PT thread to ISO 7-2, BS 21 or JIS B0253, checked with a basic or min/max step gauge rather than a parallel GO / NOT-GO pair. Body and gland fasteners are more often a parallel metric or unified thread, checked with thread plug and ring gauges to DIN ISO 1502 or ANSI/ASME B1.2.
Plain bores and shafts
A valve stem, piston or plunger running in a bore needs a controlled fit, checked with plain plug gauges for the bore and plain ring gauges for the shaft, GO members in tungsten carbide and NOT-GO in steel, to IS 3455.
Specifying the gauge
Confirm whether a port seals by a taper thread or a parallel thread with a separate gasket, since that decides the gauge family, then confirm the bore or shaft tolerance class for the plain fit. Non-standard sizes and special designs are available to drawing where the standard range does not cover a size.
Gauge families used for this inspection
Questions about pumps & valves
Which gauge families are typically used in pump and valve inspection?
Taper pipe thread gauges for pressure-tight ports, metric or unified thread plug and ring gauges for fasteners, and plain plug and ring gauges for bores and shafts.
Which standards apply?
NPT to ANSI/ASME B1.20.1, ISO 7-R / BSPT / PT taper pipe threads to ISO 7-2, BS 21 or JIS B0253, and plain plug and ring gauges to IS 3455.
How do I know if a port is taper or parallel thread?
Check the drawing for the governing standard; a taper pipe standard (NPT, BSPT, PT) seals by the thread fit itself, while a parallel standard usually seals with a separate gasket or O-ring.
What material are the plain plug and ring gauges?
GO members are made in tungsten carbide for wear resistance, with NOT-GO members in steel, in Reversible or Trilock styles depending on size.
Do you make special or non-standard gauges for pump and valve parts?
Yes, we build non-standard and special gauges to drawing to the size and feature agreed with you in advance.
How do I request a quote?
Share the thread size, standard or a drawing on our quote page and we will confirm the class, availability and pricing within one business day.
Tell us what you are inspecting.
Share your thread, standard or drawing and get the right acceptance class, certified.