Campbell Coupling Selection Guide

From the Selection Guide below, choose an appropriate coupling based on the hose type and application working pressure. Click here for the Coupling Selection Guide PDF.

NOTE: The data below is based on years of hydrostatic testing. All tests are performed to the ASTM D380 standard. We employ a safety factor based on the Rubber Manufacturers Association (RMA) recommendations of 4x working pressure (WP) for most hoses with the exception of 3x for water up to 150 psi., 5x for LP gas and 10x for steam. This means that any hose with a 4x safety factor is tested to 4000 psi., or beyond, in order to establish a 1000 psi. rating.

Hose System Components Maximum Working Pressure @ 70° (F)
Hose Size
Fitting/Coupling Attachment Hose Type2 1/2 3/4 1 1-1/4 1-1/2 2 2-1/2 3 4 6 8 10 12
Combination Nipple Short Sleeve Rubber 400 350 300 275 250 225 225 225 175 175 150 125 100
Combination Nipple Short Sleeve Chemical 200 200 200 140 130 120 110 100 50
Combination Nipple Short Sleeve PVC 125 125 100 90 85 65 60 55 40 30 20
Pin Lug Coupling Short Sleeve Rubber 275 250 225 210 200 175 150 100
Pin Lug Coupling Short Sleeve PVC 90 85 65 60 55 40 30 20
Ball & Socket Coupling3, 6 Short Sleeve Rubber 3003 2503 2253 1403 603
Ball & Socket Coupling3, 6 Short Sleeve PVC 1703 1403 1003 803 503
Crimpnology Nipple Ferrule Chem/Rubber 500 350 325 300 275 250 250 225 175
Crimpnology Nipple Ferrule Soft 200 175 150 150 125 100 75 50
FRAC Crimpnology Nipple Ferrule Rubber 400
Long Shank Nipple Long Ferrule Rubber 1000 1000 650 600 500
206 Hose Union Long Ferrule Rubber 500
Crimpnology Flange (Steel)4 Ferrule Chem/Rubber 285 285 275 250 250 225
Crimpnology Flange (SS)4 Ferrule Chem/Rubber 230 230 230 230 230 225
Campbell COBRA Cam & Groove (SS)5 Ferrule Chem/Rubber 250 250 250 150 150 100
Campbell COBRA Cam & Groove (Alum)5 Ferrule Chem/Rubber 250 200 150 125 75
Viton Ground Joint Coupling Staked Ferrule Steam 1250 1250 1250
Viton Ground Joint/Air Hammer Cplg Long Ferrule Rubber 1000 1000 1000 1000 1000 1000 650 500 400
Male Stem Long Ferrule Rubber 1000 1000 1000 1000 1000 1000 650 500 400
Male Stem Staked Ferrule Steam 1250 1250 1250
Viton Ground Joint/Air Hammer Cplg U-Bolt Clamp Rubber/Steam 1500 1250 1250 1250 1250 1250 800 500 500
Male Stem and Mender U-Bolt Clamp Rubber/Steam 1500 1250 1250 1250 1250 1250 800 500 500
UniversaLock6 Ferrule Air 300 300 300
UniversaLock6 Bolt Clamp Air 150 150 150
Universal6 Ferrule Air 150 150 150
Universal6 Bolt Clamp Air 150 150 150
Single-Lock Coupling6 Ferrule Air 300 300 300
Double-Lock Coupling6 Ferrule Air 300 300 300
ChemJoint/Male Stem Ferrule Chemical 350 400 450 325 250 250 225 225 200
ChemJoint/Male Stem Ferrule Rubber 350 400 450 425 400 350 325 300 250
ChemJoint Weld-On and Union None None 800 800 650 600 600

Temperature De-Rating Chart

When should 500 psi. be 320 psi.? When it’s hot! More

The effect of elevated temperature on any hose system is significant and often overlooked. Since the lay line of most hoses indicates the maximum WP and the maximum temperature, it can be assumed the hose assembly will achieve both at the same time. Hot hoses get soft and are more pliable, hampering the ability of the attachment to hold the couplings securely on the hose. Since Campbell’s pressure ratings are established by testing at 70F, we established a separate pressure de-rating chart for elevated temperatures.

Elevated Temperature De-rating Chart – de-rating factor applies to hose system pressure ratings
Hose Type 70° 90° 150° 200° 250° 300° 350° 400° 450° 500°
Steam 1.00 0.95 0.81 0.68 0.56 0.44 0.32 0.20 0.08 N/R
Hot Tar & Asphalt 1.00 0.95 0.81 0.68 0.56 0.44 0.32 0.20 0.08 N/R
PVC 1.00 0.82 0.30 N/R N/R N/R N/R N/R N/R N/R
Rubber 1.00 0.91 0.64 0.42 0.20 N/R N/R N/R N/R N/R
Chemical 1.00 0.91 0.64 0.42 0.20 N/R N/R N/R N/R N/R
Air 1.00 0.91 0.64 0.42 0.20 N/R N/R N/R N/R N/R
Soft 1.00 0.91 0.64 0.42 0.20 N/R N/R N/R N/R N/R

*System temperature is affected by both the media and the environment. N/R means NOT RECOMMENDED!

How the De-rating chart works:

The chart lists temperatures across the top and hose type down the left column. Based on your hose system application, locate the appropriate de-rating factor and multiply it by the hose system pressure rating in the pressure chart above.

Steam hose example:

  1. Hose – ¾” steam hose, rated to 250 psi. at 406°(F).
  2. Coupling/Attachment – Campbell Viton Seal Ground Joint Couplings with crimp ferule are rated to 1250 psi. at 70° (F).
  3. Operating temperature – 406°
  4. De-rating factor at 406° – .20
  5. Hose System de-rating – 1250 x .20 = 250 ps. *

Rubber hose example:

  1. Hose – 3″ air hose rated to 500 psi.
  2. Coupling/Attachment – Long Shank Crimpnology Nipple with Long Ferrule rated to 600 psi.
  3. Operating Temperature – 150°(F)
  4. De-rating factor – .64
  5. Hose System de-rating – 600 psi. x .64 = 384 psi. *

* After the de-rating is calculated for the fitting and attachment, check maximum working pressure of the hose. The hose system should never operate at a higher pressure than the lowest rated component. (Example: 150 psi rated hose with 500 psi rated coupling and attachment at 90°(F). The de-rating factor is .90. So, the newly calculated pressure rating is 500 x .90 = 450 psi.. Since the hose is rated to 150 psi., then the maximum working pressure of the system is still 150 psi.

On a typical summer day at any construction site, compressors crank out high pressure air to operate tools and equipment. Between the weather and the compressor motors, the compressed air gets dangerously hot. So hot, that those hoses can no longer safely operate at the intended pressure rating. Our de-rating chart shows that at 150°(F) the hose system should operate at 64% of the pressure rating given for 70°(F). That’s when 500 psi,. should be 320 psi.

Know the safety limits of hoses. Use the Campbell de-rating chart when specifying hoses at elevated temperatures.

  1. For normal fluids (not hazardous, combustible, flammable, volatile, corrosive, ammonia or LPG). Individual testing should be employed for non-normal fluids to ensure capability. Pressures shown are only valid for the fitting/coupling/attachment and hose combinations indicated and for their threaded mating parts. System working pressure does not include end pull forces. Not for plastic fittings/couplings. All hose systems must be assembled using Campbell procedures and crimp specifications. See elevated temperature derating chart above. Consult factory for reduced temperatures. Never exceed the working pressure of the lowest rated component in the hose system. Maximum working pressure includes the highest pressure the system will experience, such as spikes, surges, and water hammer effects. (For example: If a system consists of a hose rated to 150 PSI and the couplings are rated to 500 PSI, the system should never be used in excess of 150 PSI.)
  2. Hose descriptions: Air – any smooth bore rubber air or water hose. Includes most general purpose hose; Chemical – any smooth bore rubber chemical hose, including plastic lined (PTFE, UHMW, XLPE). Does not include soft tube hose; PVC – any smooth bore PVC or vinyl hose; Rubber – any smooth bore rubber hose except steam, hot tar & asphalt, chemical, and soft tube hose; Soft – any smooth bore rubber hose with a thick, soft tube. Usually gum rubber and some food­ grade hose; Steam – includes hot tar and asphalt
  3. Ball & Socket pressure ratings are based on 1.5 x WP.
  4. Due to limitations with flanges, consult factory for temperatures other than 70°F.
  5. Campbell COBRA Cam & Groove Couplings are identified by the name “Campbell” on the body, by the ferrule interlock groove, and by the part number, which includes a “C” suffix. Not for air or gas service.
  6. Maximum temperature 160°F.

Hose Assemblies vs. Hose Systems

A hose assembly is a collection of components using attachments, such as band clamps or bolt clamps.

A hose system uses Campbell’s integrated-designed fittings, couplings, ferrules, sleeves, or U-bolt clamps and is assembled using Campbell crimping procedures and specifications. A hose system is repeatable, measurable, and performance rated.

All Campbell pressure ratings are verified by extensive hydrostatic burst testing with hoses to ASTM D380 standards. Test results for specific hoses can be provided upon request.

The Safety Factor

The RMA requires that hose working pressures include a safety factor commensurate with their intended application. Most hoses are required to meet a 4x safety factor, except the following: Water hose rated under 150 PSI requires a 3x safety factor; Steam hose requires a 10x safety factor; and Hose conveying gas in a liquid state requires a 5x safety factor. (For example: a 150 PSI rated air hose has a 4x safety factor and must be successfully tested to a minimum of 600 PSI.)

Campbell’s fitting and coupling pressure ratings match the RMA safety factor requirements with most hoses. Due to the wide variety of industrial hoses, as well as variations in design, construction, and material, we cannot guarantee that our pressure ratings meet the safety factor requirement with every hose.

If you have any questions about pressure ratings, please contact Campbell Fittings.