Stainless Steel Braided Heated Hose Fittings

Selecting the proper fittings for a heated hose application is largely determined by mating the fittings to which the heated hose assembly will be attached. Once the mating fittings have been identified, the heated hose fittings should complement the mating fittings in type, size, and alloy. Even though the selection of heated hose fittings is determined by the mating fittings, it is a good idea to confirm that the fittings used in the application are appropriate for the application and any necessary changes made. Ensure that the fittings are chemically compatible with and are able to withstand the pressure and temperatures of both the media and the surrounding environment.

	Male Pipe Nipple Alloys – T304 and T316 Stainless Steel, Carbon Steel, 276 Sizes – 1/8″ thru 8″ Schedules – 40 and 80
	Hex Male Alloys – T304 and T316 Stainless Steel, Carbon Steel, Brass Sizes – 1/4″ thru 4″
	Grooved-End Fitting Alloys – T304 and T316 Stainless Steel, Carbon Steel Sizes – 1″ thru 8″ Schedule – 40
	LiveLink® Swivel Fitting Alloys – T304 Stainless Steel Sizes – 1/4″ thru 2″
	Female Union (Threaded/Socket Weld) Alloys – T304 & T316 Stainless Steel, Carbon Steel, Malleable Iron, Brass Sizes – 1/4″ thru 4″ Class – 125#, 150# (3000# Carbon Steel Only)
	Female Half Coupling (Threaded/Socket Weld) Alloys – T304 and T316 Stainless Steel, Carbon Steel Sizes – 1/4″ thru 4″ Class – 150# (3000#)
	1, 2, or 3 Piece SAE (JIC) Alloys – T316 Stainless Steel, Carbon Steel, Brass (nut only) Sizes – 1/4″ thru 2″
	45° and 90° SAE (JIC) Alloys – Stainless Steel, Carbon Steel Sizes – 1/2″ thru 2″
	Sanitary Flange Alloys – T304 and T316 Stainless Steel Sizes – 1″ thru 3″
	Slip-on Flange Alloys – T304 and T316 Stainless Steel, Carbon Steel Sizes – 1/2″ thru 12″ Class – 150#, 300#
	Plate Flange Alloys – T304 and T316 Stainless Steel, Carbon Steel Sizes – 1/2″ thru 12″ Class – 150#
	Weld Neck Flange Alloys – T304 and T316 Stainless Steel, Carbon Steel Sizes – 1/2″ thru 6″ Class – 150#, 300#
	TTMA Flange Alloys – T316 Stainless Steel, Carbon Steel Sizes – 2″ thru 6″
	C Stub with Floating Flange Alloys – T304 and T316 Stainless Steel Sizes – 1/2″ thru 10″ Schedule – 10
	A Stub with Lap Joint Flange Alloys – T304 and T316 Stainless Steel, Carbon Steel, 276 Sizes – 1/2″ thru 8″ Schedules – 10, 40
	TTMC C Stub Swivel Alloys – T304 and T316 Stainless Steel Sizes – 4″ thru 6″ Schedule – 10
	Part A and Part D (Cam-Lock) Alloys – T316 Stainless Steel, Brass, Aluminum Sizes – 1/2″ thru 8″
	Tube End Alloys – T304, T316, and T321 Stainless Steel, Carbon Steel Sizes – 1/8″ thru 8″ (seamless and welded) Wall Thickness – various
	Short and Long Radius Elbows (45° and 90°) Alloys – T304 and T316 Stainless Steel, Carbon Steel, 276 Sizes – 1/4″ thru 6″
	Reducer Alloys – T304 and T316 Stainless Steel, Carbon Steel Sizes – 3/4″ thru 6″ Schedule – 10 (40 Carbon Steel)
	Beveled Pipe End Alloys – T304 and T316 Stainless Steel, Carbon Steel, 276 Sizes – 1/8″ thru 8″ Schedules – Various
	Ground Joint Female Alloys – Carbon Steel Sizes – 1/2″ thru 4″
	Specialty Gas Nuts Alloys – Brass Sizes – A, B, C, D Thread Type – SAE and BSP

Polytetrafluoroethylene (PTFE) Heated Hose Fittings

Selecting the proper fittings for a heated hose application is largely determined by mating the fittings to which the heated hose assembly will be attached. Once the mating fittings have been identified, the heated hose fittings should complement the mating fittings in type, size, and alloy. Even though the selection of heated hose fittings is determined by the mating fittings, it is a good idea to confirm that the fittings used in the application are appropriate for the application and any necessary changes made. Ensure that the fittings are chemically compatible with and are able to withstand the pressure and temperatures of both the media and the surrounding environment.

	Male Pipe Alloys – T303 Stainless Steel, Carbon Steel, Brass Sizes – 1/8″ thru 11.5″
	Female Swivel JIC Alloys – T303 Stainless Steel, Carbon Steel, Brass Sizes – 3/8″ thru 12″
	Sanitary Fitting Alloys – Stainless Steel Sizes – 1/2″ thru 3″
	Female Pipe Fitting Alloys – T304 Stainless Steel, Brass Sizes – 1/4″ thru 18″
	Tube End Fitting Alloys – T303 Stainless Steel Sizes – 1/4″ through 3/4″
	Power Trim Fittings (Paint Spray Swivel) Alloys – T303 Stainless Steel, Carbon Steel Sizes – 3/8″ thru 24

To calculate a working pressure derated for elevated temperature, multiply the hose working pressure shown in the chart by the appropriate derating factor below.

Note: The working pressure of an assembly at elevated temperatures may be affected by fitting type, material, and method of attachment.

Working Pressure Derating Factor

*T301 is not listed in B31.1, but its tensile and yields are identical to T304 per ASM Metals Reference Book 3rd Ed. Pg 364
**Do not use for temperatures lower than 32°F

Depending on your application, we have several outer jacket options for your heated hose. The options listed below are our most common jacket options, but we have other options depending on your transfer medium and the environment where it will be in use.

General Purpose, Flexible and Dry Environments

Braided from 10 mil polyethylene terephthalate monofilament yarns. This material has a wide operating temperature range, is resistant to chemical degradation, UV radiation, and abrasion. This sleeve cuts easily and cleanly with a hot knife and once installed, will beautify and protect any heated hose or cable application.
This material is flame retardant, cut & abrasion resistant, and has a temperature range of -94°F to 257°F and is perfect for heated hose assemblies that are in a general, dry environment. This material is used in our heated hoses requiring extra flexibility.

Corrosive & Wet Environments

Industrial grade Pyrojacket® withstands repeated exposures to molten steel, molten aluminum and molten glass up to 3000°F (1650°C). The heavy coating of our proprietary iron oxide red silicone rubber compound sheds molten metal splash immediately, so very little heat transfer occurs.
Industrial grade Pyrojacket® will withstand continuous exposure to 500° F (260°C); up to 2000°F (1090°C) for 15-20 minutes; and up to 3000°F (1650°C) for 15-30 seconds. When exposed to flame, the silicone rubber transforms into a crust, creating a protective SiO2 refractory layer.
Industrial grade Pyrojacket® is constructed from high bulk glass fiber knitted sleeve. Excellent modulus of elasticity makes it an excellent choice for bundling hoses, tubes and cables in a variety of hostile environments.

Extreme Environment – Corrosive and Wet Environments

For heavier usage environments, our heated hoses are available with a thermoplastic rubber reinforced jacket with a wire helix. They have a superior temperature range of -60°F to 275°F, good abrasion resistance and resists oil and chemicals.

Extreme Environment With Wear Strip – Corrosive and Wet Environments

For wet, extreme, heavy use environments, our heated hoses are available with a thermoplastic rubber reinforced with a wire helix and an external polypropylene wear strip for superior drag resistance, preventing premature wear-through. They have a temperature range of -60°F to 275°F, good abrasion resistance and resists chemicals. This heated hose jacket has a heavier wall and the wear strip is molecularly bonded and will not delaminate. Ideal for applications where dragging is involved.

To calculate the proper length of a heated hose assembly, you need to:

1. Verify that the installation is properly designed
   • Do not torque the hose
   • Do not overbend the hose
   • Do not compress the hose
2. Calculate the live length of the assembly – The live length of the assembly is the amount of active (flexible) hose in an assembly; that is, the hose between the braid collars.
3. Calculate the overall length of the assembly – Overall length is equal to the live length plus the lengths of the braid collars and fittings. When adding fitting lengths, be aware that the points from which measurements should be taken vary for different fitting types. When calculating overall length for assemblies with threaded fittings, remember to account for the length of thread that is lost by threading into the mating connection.

	JIC/SAE-type fittings are measured from the seat of the fitting.
	Elbows and other fittings with a radius are measured from the centerline of the fitting.
	Flanges are measured from the flange face or from the face of the stub end if one is used.
	Threaded fittings are measured to the end of the fitting.

For the following formulas:

L = Live length of hose (inches)
T = Travel (inches)
S = Hose outside diameter (see product data pages)

Verify that the installed radius is greater than the stated Minimum Bend Radius for the hose at the required working pressure.

Verify that the centerline of the hose remains in the same plane during cycling to prevent twisting the assembly.

CONSTANT RADIUS TRAVELING LOOP (A-Loop)

VARIABLE RADIUS TRAVELING LOOP (B-Loop)

LATERAL OFFSET

ANGULAR DEFLECTION

VERTICAL LOOP WITH MOVEMENT IN TWO DIRECTIONS (Combination Loop)

To help us design a heated hose assembly for your particular application, the following design parameters must be determined.

1. Size

The diameter of the connections to which the assembly will be installed is needed to provide a proper fit. This information is required.

2. Temperature

As the temperature to which the assembly is exposed (internally and externally) increases, the strength of the assembly’s components decreases. Also, the coldest temperature to which the hose will be exposed can affect the assembly procedure and/or fitting materials. If you do not provide this information, it will be assumed that the temperatures are 70° F.

3. Application

This refers to the configuration in which the assembly is installed. This includes both the dimensions of the assembly, as well as the details of any movement that the assembly will experience. This information is necessary to determine assembly length and required flexibility.

4. Media

Identify all chemicals to which the assembly will be exposed, both internally and externally. This is important since you must be sure the assembly’s components are chemically compatible with the media going through the hose, as well as the environment in which the hose is to be installed. If no media is given, it will be assumed that both the media and the external environment are compatible with all of the available materials for each component.

5. Pressure

Identify the internal pressure to which the assembly will be exposed. Also, determine if the pressure is constant or if there are cycles or spikes. This information is important to determine if the assembly is strong enough for the application. If no pressure is given it will be assumed that the pressure is low and there are no pressure surges or spikes.

6. End Fittings

Identify the necessary end fittings. This is required since fittings for the assembly must be chosen to properly fit the mating connections.

7. Dynamics

Identify the velocity at which the media will flow through the assembly. Since corrugated metal hose does not have a smooth interior, rapid media flow can create a resonant frequency that will cause the hose to vibrate and prematurely fail. If no velocity is given, it will be assumed that the velocity is not fast enough to affect the assembly’s performance.

Assembly Components

The various components that make up a heated hose assembly, and what information engineering will need in order to make a hose assembly for your application.

In order to produce an assembly, the fabricator will need answers to the following five questions:

1. Hose (type, allow & size)
2. Fittings (type, alloy & size for each end)
3. Length (either the overall length or live length)
4. Jacket (depending on your environment)
5. Leads ( power lead & thermocouple location)

When selecting a hose, you must consider three variables: pressure-carrying capability, flexibility, and chemical compatibility.

1. Pressure Carrying Capability

The hose must be strong enough to handle the pressures to which it will be exposed. To determine hose pressure capability, consult sales for the “Maximum Working Pressure” stated for the hose. The Maximum Working Pressure must be reduced for each of the following circumstances:

• Temperature – As temperature increases, hose working pressure decreases. After you have determined the proper alloy (see “Chemical Compatibility” below) go to the “Derating Factor” and match the alloy of the hose and braid with the highest temperature to which they will be exposed (either internally or externally) to obtain the proper derating factors. Then multiply the hose’s Maximum Working Pressure by the most-limiting temperature derating factor.
• Dynamic Pressure – Pulsating, surge, or shock pressures, like those encountered with quick opening or closing valves, can inflict severe damage on a hose. If your application entails pulsating pressures, the working pressure should be de-rated by half. If your application entails shock pressures, de-rate the stated working pressure to 1/6 of its value.

Example:
1” Annuflex hose – T321 stainless steel hose and T304 stainless steel braid @ 500° F with shock pressures.

Catalog Maximum Working Pressure = 718 psi

Temperature Derating Factor at 500° F. = 0.88; and the Pressure Derating Factor = 1/6
Maximum Application Working Pressure = 718 psi x 0.88 x 1/6 = 105.31 psi

2. Flexibility

Confirm that the hose’s minimum bend radius is less than the bend radius required for the application. Increasing the installed radius of the hose will reduce fatigue on the corrugations, increasing assembly life. Care should also be taken for applications with vibration. Contact Protherm’s Inside Sales Department if excessive vibration is present.

3. Chemical Compatibility

You must choose a material for the hose and braid that is compatible with the media being conveyed through the hose, as well as the environment in which the hose is to be installed. When determining chemical compatibility, it is important to know the temperature and concentration of the chemical(s). Although there are many resources to confirm chemical compatibility, two of the industry standards that you may use are the National Association of Corrosion Engineers (NACE) and the Compass Corrosion Guides. You may also contact Protherm’s Inside Sales Department, which can check these sources for you.