The SHPA is the compact ultra high pressure option: 4.0 GPM at 7,000 PSI, running at 1,450 RPM on an 18 mm solid shaft.

That 18 mm shaft is the point of the series. It is a smaller frame than the rest of AR’s ultra high pressure line, which makes it the one that fits where a bigger pump does not.

SHPA4G70HN specifications

Check the shaft before anything else

The 18 mm shaft is smaller than the 24 mm used across most of the industrial range. That has consequences:

• Couplings, sheaves and rail hardware specified for a 24 mm pump will not fit
• Torque capacity is lower, so the coupling has to be selected carefully rather than assumed
• The overall package is genuinely smaller, which is the reason to choose it

If you are replacing an existing pump, confirm the shaft before ordering. If you need 24 mm at similar pressure, the SHP series covers 4 to 5.8 GPM at 7,250 PSI on that shaft.

Low flow, high impact

4 GPM sounds modest next to an 18 GPM washdown pump, and that is exactly the trade. At 7,000 PSI the energy is concentrated rather than spread, and 4 GPM at that pressure is 19.2 EBHP, which is the same shaft power as 13.2 GPM at 2,200.

The practical consequence: the SHPA removes coating that no amount of volume will touch, and it does not rinse a truck quickly. Pick the corner of the trade you actually need.

SHPA4G70HN applications

• Pipeline cleaning and hydrostatic testing in oil, gas and municipal infrastructure
• Steel and concrete surface preparation, removing coatings, paint and rust without abrasive blasting
• Shipyards and marine: hull coating removal and heavy marine buildup
• Precision jetting and waterjet-assisted cutting of stone, composites and metals
• Municipal: bridge cleaning, graffiti removal, high-pressure sewer work
• Heavy manufacturing: machinery, tanks and production equipment

Working safely at 7,000 PSI

The same rules as the rest of the ultra high pressure range. Every downstream component rated with margin, including couplers. Primary relief valve fitted, burst disc as a secondary. Operators trained for this pressure class specifically, because injection injuries look minor and are not.

Nozzle wear matters more here than anywhere else on the site: a worn orifice quietly drops your pressure, and the machine feels tired rather than broken.

Why nickel-plated brass

At this pressure a corrosion pit is a stress concentration, not a cosmetic issue. Nickel plating resists the oxidation and chemical attack that pit plain brass, and these pumps typically work in humid, marine or chemical environments where that matters.

Servicing the SHPA4G70HN

Rebuildable with kits for valves, pistons, water seals, oil seals and piston guides, plus rail kits in 1-1/4 in, 2-1/2 in and U-bracket for mounting. Confirm part numbers against the SHPA specifically rather than the SHP; the frames differ.

Filter the inlet, change the oil on schedule, and replace seals before they fail rather than after. At 7,000 PSI a failed seal takes other parts with it.

Send your shaft size, target pressure and available motor and you will get the right frame the first time.