What this manual covers

Swagelok catalog MS-01-138 is a dedicated 20-page quick-connect catalog rather than a general product handbook. It covers four product families: QC instrumentation quick-connects, QF full-flow quick-connects, QM miniature quick-connects, and QTM PTFE-sealed quick-connects. This landing page turns the catalog into a web selection path and keeps the original PDF available for dimensional tables, complete ordering numbers, pressure-temperature derating, and safety notes.

All matching products remain in their original website taxonomy, such as Tube Fittings or Pipe Fittings. The model list below is assembled from Swagelok ordering-number prefixes, so this editorial hub does not create or force a new global product category.

Series comparison

Series	Catalog sizes	Shutoff / flow style	Typical reason to select it	Materials highlighted in MS-01-138
QC	QC4, QC6, QC8	SESO and DESO	General instrumentation service, broad connection choice, keyed identification	316 stainless steel or brass
QF	QF4, QF8, QF12, QF16	Full flow	Minimum internal restriction and higher flow capacity	316 stainless steel or brass
QM	QM2	SESO / compact coupling	Small envelope, low dead volume and fingertip operation	316 stainless steel or brass
QTM	QTM2, QTM4, QTM8	Flush valve, PTFE sealed	Reduced spillage, recessed seals, media compatibility and keyed lines	316 stainless steel or Alloy 400

Core terms used throughout the catalog

• Coupling compatibility: a stem fits a body of the same series and size. A QC4 stem fits a QC4 body; a QC8 stem fits a QC8 body. Do not assume compatibility across series or nominal sizes.
• SESO — single-end shutoff: the stem has no valve and remains open after uncoupling. The system must be depressurized before a SESO coupling is disconnected.
• DESO — double-end shutoff: the stem contains a valve and shuts off when uncoupled. The body and stem both provide shutoff behavior.
• Spillage: the amount of system fluid released during uncoupling, stated for DESO designs.
• Air inclusion: the amount of trapped air introduced into the system when a DESO body and stem are coupled.
• Flow coefficient: catalog Cv values are averages and may vary by ±10%. Values assume like end connections; for unlike end connections, the catalog instructs users to average the two Cv values.

A reliable selection sequence

1. Define the process duty. Record fluid, concentration, cleanliness, pressure, temperature, flow target, cycle frequency and acceptable leakage or spillage.
2. Choose the family. Use QC for broad instrumentation selection, QF where unrestricted flow is the priority, QM where space and internal volume are limited, or QTM for a PTFE-sealed flush-valve architecture.
3. Choose the nominal coupling size. Body and stem must carry the same series and size code.
4. Choose flow/shutoff behavior. Confirm SESO, DESO, or full-flow operation before selecting the body and stem.
5. Select body material and seals. Confirm compatibility of every wetted material, not only the body alloy. Standard and optional O-rings differ by series.
6. Select both end connections. Available patterns include Swagelok tube fittings, NPT, ISO/BSP tapered and parallel threads, and additional catalog-specific connections.
7. Check every operating state. Coupled pressure, uncoupled pressure, coupling/uncoupling pressure and temperature limits are not necessarily the same.
8. Add identification and protection. Keyed variants help prevent cross-connection; protectors limit dirt ingress and handling damage but are not pressure-containing devices.
9. Verify the complete ordering number. Use the series page and PDF tables to confirm base number, material prefix, seal suffix, key code and other options.

Quick performance reference at approximately 20 °C

Series / size	Catalog reference value	Practical interpretation
QC4	Spillage 0.3 cm³; air inclusion 0.3 cm³; max recommended water flow 4 US gal/min (15 L/min)	Small general instrumentation coupling
QC6	Spillage 1.0 cm³; air inclusion 1.0 cm³; max recommended water flow 6 US gal/min (22 L/min)	Mid-size instrumentation coupling
QC8	Spillage 3.0 cm³; air inclusion 3.0 cm³; max recommended water flow 10 US gal/min (37 L/min)	Larger QC flow path
QM2	Spillage 0.1 cm³; air inclusion 0.1 cm³; max recommended water flow 1 US gal/min (3.8 L/min)	Compact, low-volume service
QTM2 / QTM4 / QTM8	Max recommended water flow 15 / 35 / 50 US gal/min (56 / 130 / 180 L/min)	Increasing flush-valve flow capacity

These are selection references, not a substitute for the complete pressure-temperature and connection tables in the PDF.

Keyed line identification

Keyed QC and QTM variants mechanically limit incorrect cross-connection. The catalog identifies eight key/color combinations: K1 black, K2 orange, K3 green, K4 yellow, K5 blue, K6 white, K7 purple, and K8 brown. QC keyed availability depends on size and configuration. QTM2 and QTM4 list K1 through K8, while QTM8 is limited to K1 through K4. Treat the key code as part of both the body and matching stem specification.

Operating and maintenance checklist

• Install filtration upstream where contamination could damage seals or valve surfaces.
• Use body and stem protectors or dust caps while disconnected.
• Align the components during coupling and uncoupling; support hoses to prevent side loading.
• Couple, uncouple and perform cleaning operations at room temperature unless a reviewed procedure states otherwise.
• Relubricate stem seal O-rings at the maintenance interval required by the service.
• Do not rotate a quick-connect while it is coupled.
• Do not insert tools or foreign objects into uncoupled bodies or stems.
• Observe the catalog's restricted pressure ratings during coupling and uncoupling.
• Never uncouple a single-end shutoff quick-connect while pressurized.

For final approval, use the downloadable MS-01-138 manual together with the process design basis and the exact model record.