QM2 application profile

The QM2 is the miniature family in MS-01-138. It is designed for lightweight fingertip operation, a small installation envelope and low dead volume. Typical uses include compact instrument panels, sample systems, laboratory equipment and low-flow gas or liquid lines where the physical size of QC or QF hardware is excessive.

QM2 still requires the same disciplined selection as a larger coupling: matching body and stem, correct shutoff behavior, compatible wetted materials, suitable O-ring, exact connection and verified pressure-temperature limits.

Key catalog values

Property	QM2 reference
Coupled pressure, 316 SS, about 40 to 100 °F	4000 psig (275 bar)
Coupled pressure, brass, about 40 to 100 °F	2000 psig (137 bar)
Uncoupled / coupling pressure at about 70 °F	100 psig (6.8 bar)
Spillage, DESO	0.1 cm³
Air inclusion, DESO	0.1 cm³
Maximum recommended water flow	1 US gal/min (3.8 L/min)

The coupled pressure rating is not permission to disconnect at that pressure. Coupling and uncoupling limits are much lower, and SESO stems must not be disconnected under pressure.

Shutoff selection

QM2 is available with the same core distinction used by the QC family:

• SESO stem: no stem valve; the stem remains open when uncoupled. Select it only where the line can be positively isolated, depressurized and safely managed.
• DESO stem: includes a shutoff valve. It is preferred where fluid containment is required on both sides. Review the 0.1 cm³ spillage and air-inclusion figures for sensitive sample volumes.

In micro-volume analytical service, even 0.1 cm³ may be significant. Consider its effect on sample dilution, purge time, oxygen ingress or hazardous-fluid release.

Materials, seals and ordering suffixes

QM2 body material is selected with the prefix:

• SS — 316 stainless steel.
• B — brass.

The standard or optional O-ring is identified by the complete ordering number. MS-01-138 lists suffixes including EP for ethylene propylene and KZ/KR-family options for cataloged alternative elastomers. Always verify the exact suffix against the current table and process compatibility; similar-looking suffixes across Swagelok product families should not be assumed to mean the same construction.

Connections and flow-path review

QM2 is associated with small tubing and thread connections. A website model such as SS-QM2-S-100 identifies a stainless QM2 stem with a 1/16 in. Swagelok tube-fitting connection. When reviewing a compact assembly, check:

• actual tube outside diameter and wall thickness;
• whether the mating half is a body, SESO stem or DESO stem;
• minimum internal orifice and required Cv;
• insertion depth plus finger access to the sleeve;
• tube support so the small coupling is not carrying the hose or instrument load;
• purge volume downstream of the connection.

When QM2 is—and is not—the best choice

Choose QM2 when installation space and internal volume dominate and the required flow is within its small-bore capability. Move to QC4 when broader body/stem, end-connection, keyed or protector choices are more important. Move to QF when an unrestricted high-flow path is required. Review QTM when PTFE sealing, recessed seals or flush-valve behavior is the primary requirement.

Procurement checklist

To quote a QM2 assembly, provide: exact body and stem ordering numbers; stainless steel or brass; SESO or DESO requirement; tube or thread connection; process fluid and cleaning agent; maximum coupled pressure and temperature; pressure during connection/disconnection; acceptable spillage and air inclusion; seal requirement; and any cleaning, packaging or certification need.

The site currently has a limited QM model set. The downloadable PDF remains the reference for identifying cataloged combinations not yet represented in the product grid.