Selecting Gland Packing for Pumps

Pump stuffing boxes see continuous shaft rotation, so packing is selected from three numbers: shaft surface speed, stuffing-box pressure and temperature. A packing that is chemically right but runs too fast or too hot will fail early.

Match material to duty

Service	Recommended packing
Clean water, mild duties	PTFE, PTFE-impregnated
Abrasive slurry, ash, mine dewatering	Aramid or aramid-outer
Hot oil, steam, boilers	Graphite / carbon fiber
Aggressive chemicals	PTFE, graphite (avoid oxidizers)
High-temperature, non-abrasive	Carbon / flexible graphite

Sizing and ring stack

Use square-section braid whose size matches the stuffing-box width.
A typical stack is 4–6 rings; a lantern ring with a flush or quench connection helps on dirty or hot service.

Installation that lasts

Cut each ring square (45° bias lap) and stagger the joints around the box.
Tighten in stages; run, observe, then re-torque as the packing beds in.
Never over-compress — excess gland stress burns the shaft and the packing.

See also how to choose the right gland packing and the packing vs mechanical seal comparison.

Frequently Asked Questions

How many rings of packing go in a pump stuffing box?

Usually 4 to 6 rings of square braid, sized to the box width. Very shallow boxes may take fewer; a lantern ring is added in the middle when a flush or quench is needed.

What packing should I use for an abrasive slurry pump?

Specify aramid or an aramid-outer braid. Aramid resists cut and abrasion from suspended solids; pair it with a PTFE or graphite core to keep friction low.

Why does my pump packing leak after a few weeks?

Common causes are under-tightening, shaft runout beyond the packing tolerance, or thermal cycling that relaxes the set. Re-torque in stages and verify shaft condition; graphite packs hold adjustment better under heat.

Can I run packing on a high-speed pump?

Yes, but pick a low-friction yarn (PTFE or graphite) and control gland stress and flush cooling. Very high surface speeds may push you toward a mechanical seal instead.