Proco Style R-6201

The Proco Style R-6201 flexible metal reducing connector has been designed to control a variety of mechanical stresses, such as:

  • Vibration control
  • Noise reduction
  • Relief from system stressors
  • Prevention of system shock
  • Compensation for misalignment and movement

Ordinary flexible metal hoses can fail to operate properly when subjected to high pressures; adding a flexible restraint, such as a metal braid, allows the hose to adequately withstand the specified internal pressure and prevent elongation. The woven metal braid is designed to fit over the metal hose, and to be strong enough to withstand elongation up to the full pressure rating of the hose.

Flexible hoses and braids can be made from a variety of different metals, to suit even the most diverse needs.

For more information about the features and benefits of the Proco Style R-6201 flexible metal pump connector, download our brochure.

For up-to-date pricing and availability information, contact PROCO today.

Expansion Joint Size: ID x ID x LengthStockLateral OffsetWorking Press (PSI)Approx. Unit Ship Weight
IntermittentPermanent@ 70°F@ 300°F
3 x 2 x 9S1/8″3/8″34530314
4 x 2 x 9S1/8″3/8″45540014
4 x 3 x 9S1/8″3/8″28925416
5 x 3 x 9S1/8″3/8″28925422
5 x 4 x 9S1/8″3/8″30026425
6 x 3 x 9S1/8″3/8″28925423
6 x 4 x 9S1/8″3/8″30026430
6 x 5 x 11S1/8″3/8″22019335
8 x 4 x 9S1/8″3/8″30026458
8 x 5 x 11S1/8″3/8″22019358
8 x 6 x 11S1/8″3/8″20017661
10 x 6 x 11S1/8″3/8″20017680
10 x 8 x 12S1/8″3/8″19016785
12 x 8 x 12S1/8″3/8″190167105
12 x 10 x 13S1/8″3/8″150132135
14 x 10 x 13X1/8″3/8″120105140
14 x 12 x 14X1/8″3/8″10088145

1. “S” Indicates stocked item.
2. “X” Denotes 1-2 week shipment time.

Temp °FMaterial
Bronze304 SS321 SS
500 .77.78
600 .73.74
100 .69.70
800 .64.66
900 .58.62
1000  .60
1100  .58
1200  .55
1300  .50
1400  .44
1500  .40

Temperature Correction Factors
1. Determine maximum operating temperature.
2. Locate appropriate correction factor above.
3. Multiply maximum working pressure by correction factor at temperature for acceptable rating.

Service temperature for a braided flexible metal pump connector has a negative affect on the amount of maximum pressure to which it can be subjected. The table above should be used to calculate the safe working pressure based on the elevated temperature the braided metal pump connector is operating under. (Working Pressure X Elevated Temperature Conversion Figure = Safe Working Pressure.)

Correct placement is essential to the proper functionality and lifespan of a flexible connector. For best results, place the Proco Style R-6201 flexible connector adjacent to rotating equipment, in a straight line, without any offset, to help isolate the piping system from excessive vibration and noise.

Braided flexible metal connectors must be installed at or below the listed permanent lateral offset values listed in the Proco R-6201 Brochure.

For more detailed information, download the PROCO Style R-6201 Brochure.



The information in the table below is to be used as a guide for the proper selection of braided metal pump connector materials (both hose and braid), based on the chemicals used.
This data should not be construed as advice on which combination to use, or not use; final responsibility lies with the system designer or operator for correct material selection based on flow media.
It is suggested that you include flow media information on the “Connector Specification Data Sheet,” found at the back of the PROCO R-6201 Brochure.
For more information, download the PROCO R-6201 Brochure here.

Corrosion Rate:
A – RESISTANT•••••••••••••••••••••••••••••••••••••less than .00035 inch penetration per month.
B – PARTIALLY RESISTANT•••••••••••••••••0035 inch penetration per month.
C – NON RESISTANT••••••••••••••••••••••••••••greater than .0035 inch penetration per month.

ChemicalTemp. °F.304,321 S.S.Carbon SteelBronze
 Acetic Acid 5%, 20% Agitated or Aerated 70° A C C
      50%70° A C C
      50%. 80%Boiling C C C
      80%70° A C C
      100%70° A C C
      100%Boiling C C C
      100%-150 lbs. Pressure400° C C C
Acetic Acid Vapors, 30%Hot C C C
      100%Hot C C C
Acetyl ChlorideCold B³ C B
 Boiling B³ C B
Acetylene Concentrated70° A A C²
      Commercially Pure70° A A C²
Acid Salt Mixture    
      10% H2SO4 Sp. G. 1.07 + 2% FeSO4 Ο 5 H2OBoiling A³, 4 C C
Acid Salt Mixture    
      10% H2SO4Sp. G. 1.07+2% FeSO4 Ο 7 H2OBoiling A³,4 C C
Alcohol, Ethyl, 70° & Boiling70° A A A
Alcohol, Methyl70° A A A
 Boiling C C A
Aluminum Acetate, Saturated70° A C C
 Boiling A C C
Aluminum Chloride    
      10% Quiescent70° C C C
      25% Quiescent70° A³,4 C C
Aluminum Fluoride70°C C C
Aluminum Hydroxide, Saturated70° A A4 A
Aluminum Sulphate, 5%150° A C C
      10%70° A C C
      10%Boiling B C C
      Saturated70° A C C
      SaturatedBoiling B C C
Aluminum Potassium Sulphate:    
      (Alum) 2%-10%70° A C B
      10%Boiling B C C
      SaturatedBoiling C C C
Ammonia (Anhydrous)    
      All Concentrations70° A A A
      GasHot C C C
Ammonia Liquor70° A C C
 Boiling A C C
Ammonium Bicarbonate70° A C C
 Hot A C C
Ammonium Bromide70° B C C
Ammonium Carbonate 1% & 5%70° A A C
Ammonium Chloride 1%70° A³,4 B C
      10%Boiling A³,4 C C
      28%Boiling B³,4 C C
      50%Boiling B³,4 C C
Ammonium Hydroxide: All Concentrations70° A B C
Ammonium Monophosphate70° A B C
Ammonium Nitrate:    
      All Concentrate Agitated70° A C C²
      All Concentrate Aerated70° A C C²
      All Concentrate SaturatedBoiling A C C²
Ammonium Perchlorate 10%Boiling A³,4 B C
Ammonium Persulphate 5%70° A C C
Ammonium Phosphate 5%70° A B C
Ammonium Sulphate    
      1% Aerated or Agitated70° A C C
      5% Aerated & Agitated70° A C C
      10% & SaturatedBoiling B4 C C
Ammonium Sulphate, 70% Boiling70° A C C
Barium Carbonate70° A B A
Barium Chloride 5% & Saturated70° A3,4 C B
Barium Hydroxide Aqueous SolutionHot A B A
Barium Nitrate Aqueous SolutionHot A B 
Barium Sulphate70° A  A
Barium Sulphide Saturated Solution70° A C C
Beer (Barley, Malt, &Hops)70° A C A
      3.5% – 4.5% Alcohol160° A C A
 Benzene (Benzol) 70° or Hot 70° A B A
 Benzoic Acid 70° A A A
 Borax 5% Hot A B A
Boric Acid    
      5% Solution, 70° or Hot70° A C A
      5% SolutionBoiling A C A
      Saturated Solution70° A3,4 C B
      Saturated SolutionBoiling A3,4 C C
Bromine Water70° C C C
Butyl Acetate  A B 
Calcium Chloride Dilute or Concen. Solution70° B3,4 C B
Calcium Chlorohypochlorite    
      (Bleaching Powder) 1%70° C C B
      (Bleaching Powder) 5%70° C C B
Calcium Hypochlorite, 2%70° B4 C B
Calcium Hydroxide, 10-20%Boiling A C A
Calcium Sulphate, Saturated70° A C A
Carbonic Acid Saturated Solution70° A C A
Carbolic Acid 70° A C B
Carbolic Acid Boiling A C B
Carbon Bisulfide 70° A B B
Carbon Monoxide Gas 1400° A A C
Carbon Monoxide Gas 14390° A A C
Carbon Tetrachloride    
      Commercially Pure 70° A3,4 B A
      Dry Commercially Pure Boiling A3,4 B A
      Commercial + 1% Water  C C B
Chloracetic Acid 70° C C B
Chlorbenzol Concentrate Pure Dry 70° A B B
Chloric Acid 70° C C C
Chlorine Gas (Dry) 70° C B A
      (Moist) 70° C C C
Chlorinated Water, Saturated  C C 
Chloroform 70° A A A
Chromic Acid    
      5% Commercially Pure 70° A C C
       10% 70° C C C
 Chromic Acid    
       10% Commercially Pure Boiling C C C
      50% Commercially Pure 70° C C C
      50% Commercially Pure Boiling C C C
      Commercial 50% (Cont. SO3) 70° C C C
      Commercial 50% (Cont. SO3) Boiling C C C
Chromium Plating Bath 70° A B C
Citric Acid 5% Still 70°-150° A C A
      15% Still 70° A C B
      15% or Concentrated Boiling B C B
Coffee RSC Boiling A C A
Copper Acetate (Saturated Solution) 70° A C 
Copper Carbonate (Sat. Sol.) in 442% NH4OH  A  C
Copper Chloride,    
      1% Agitated 70° B3,4 C C
      1% Aerated 70° B3,4 C C
       5% Agitated 70° C C C
       5% Aerated 70° C C C
Copper Cyanide (Saturated Solution) Boiling A C C
Copper Nitrate    
      1% Still, Agitated & Aerated 70° A CC
      5% Still, Agitated & Aerated 70° A C C
       50% Aqueous Solution Hot A C C
Copper Sulphate    
      5% Agitated Still or Aerated 70° A C B
      Saturated Solution Boiling A C B
Cresote (Cool Tar)HotABA
Creosote Oil Hot A B B
Dichloroethane (Dry) Boiling A C C
Dyewood Liquor 70° A1 C 
Epsom Salt (Magnesium Solution) Hot & Cold A3,4 C A
Ethyl Acetate (Concentrated Solution) 70° A B A
Ethyl Chloride 70°A3,4 B B
Ethylene Chloride 70° A3,4 B B
Ethylene Glycol 70° A B A
Ferric Chloride    
       1% Solution Still 70° B3,4 C C
      1% Solution Boiling C C C
      5% Solution, Agitated, Aerated 70° C C C
Ferric Hydroxide  A C 
Ferric Nitrate    
      1-5% Quiescent or Agitated 70° A C C
      1-5% Aerated 70° A C C
 Ferric Sulphate    
      1-5% Quiescent or Agitated 70° A4 C C
      1-5% Aerated 70° A4 C C
       10% Boiling A4 C C
Ferrous Chloride: Saturated Solution 70° C C B
Ferrous Sulphate: Dilute Solution 70° A C B
Fluorine (Gas) Moist 70° C C C
Formaldehyde 40% Solution  A4 B A
Formic Acid, 5% Still 70° B C B
 5% Still 150° B C B
Fuel Oil Hot A B A
      Containing Sulphuric Acid  C C C
Gallic Acid, 5% 70°-150° A C 
      Saturated 212° A C 
 Gasoline 70° A B A
 Hydrochloric Acid: All Concentrations 70° C C C


ChemicalTemp. °F.304,321 S.S.Carbon SteelBronze
 Hydrocyanic Acid70° A C C
 Hydrofluric Acid70° C C C
 Hydrofluosilic Acid 70° C C B
 Hydrogen Sulphide (Dry) 70° A B A
       (Wet) 70° B1 C C
 Hyposulphite Soda  A C 
 Iodine 70° C C C
 Kerosene 70° A B A
 Ketchup, Quiescent 70°-150° A4 C 
 Lactic, Acid 1% 70° A C B
       1% Boiling A C C
       5% 70° A C B
       5% Boiling B C C
       10% 70° B C B
       10% Boiling C C C
       Concentrated 70° B C B
       Concentrated Boiling C C C
 Lead Acetate 5% Boiling A C 
 Linseed Oil 70° A B B
 Plus 3% H2SO4 390° B C C
 Magnesium Chloride    
       1% Quiescent 70° A3,4 C B
       1% Quiescent Hot C C B
       5% Quiescent 70° A3,4 C B
       5% Quiescent Hot C C B
 Magnesium Oxychloride 70° C C 
 Magnesium Sulphate Hot & Cold A C A
 Malic Acid Hot & Cold B C 
 Mercuric Chloride Dilute Solution 70° C C C
 Methanol (Methyl Alcohol)  A B A
 Mixed Acids 53% H2SO4+45% HNO3 Cold A C C
 Muriatic Acid 70° C C C
 Naphtha, Crude 70° A B B
 Naphtha, Pure 70° A B B
 Naphthalene Sulfonic Solution 70° A C 
 Nickel Chloride Solution 70° A3,4 C B
 Nitrating Solution Cold & Hot B  B
 Nickel Sulphate Cold & Hot A C A
 Nitric Acid    
       5%-442%-70% Boiling A C C
       65% 70° A C C
       65% Boiling B C C
       Concentrated 70° A C C
       Concentrated Boiling C C C
       Fuming Concentrated 70°-110° A C C
       Fuming Concentrated Boiling C C C
 Nitrous Acid 5% 70° A C C
 Oils, Crude Cold & Hot A1  
 Oleic Acid 70°-400° A4 B B
       5%-10% 70° & Boiling A C B
       10% Boiling C C B
       25%-50% Boiling C C B
 Phenol (See Carbolic Acid)    
 Petroleum Ether  A B 
 Phosphoric Acid    
       1% 70° A C C
       1% Boiling A C C
       1%-45 lbs. Pressure 284° A C C
       5% Quiescent or Agitated 70° A C C
       5% Aerated 70° A C C
       10% Quiescent 70° C C C
       10% Agitated or Aerated 70° C C C
       10%-50% Boiling A C C
       80% 70° C C C
       80% 230° C C C
       85% Boiling C C C
 Pictic Acid 70° A C C
 Potassium Bichromate, 25% 70° A C C
       25% Boiling A  C
 Potassium Bromide 70° B4 C B
 Potassium Carbonate 1% 70° A B B
 Potassium Carbonate Hot A B C
 Potassium Chlorate: Saturated at 212° Boiling A3 B C
 Potassium Chloride    
       1% Quiescent 70° A3,4 C B
       1% Agitated or Aerated 70° A3 C B
       5% Quiescent 70° A3,4 C B
       5% Agitated or Aerated 70° A3 C B
       5% Boiling A3 C B
 Potassium Chromium Sulphate, 5% 70° A4 C B
       Sp. G. 1.6 Boiling C C C
 Potassium Cyanide 70° A B C
Potassium Ferricyanide, 5%-25%70°AC 
Potassium Ferrocyanide, 5%70°AC 
Potassium Hydroxide, 5%70°ACB
Potassium Hypochlorite70°BCC
Potassium Nitrate    
      1%-5% Still or Agitated70°ACB
      1%-5% Aerated70°ACB
Potassium Permanganate, 5%70°AB 
Potassium Sulphate    
      1%-5% Still or Agitated70°AB 
      1%-5% Aerated70°ABA
Potassium Sulphide (Salt) A3,4C 
Sea Water70°A3,4CB
Sewage A A
Silver Bromide B4CC
Silver Chloride C3,4CC
Silver Nitrate ACC
Sodium Acetate (Moist) A4C 
Sodium Bicarbonate    
      All Concentrations70°ACB
Sodium Bisulphate, Solution70°ACB
Saturated Solution70°CCB
2g.+1g. H2SO4 liter68°CCB
Sodium Carbonate, 5%70°-150°A3,4BB
       5%-50% Boiling A3,4 B B
 Sodium Chloride, 5% Still 70°-150° A3,4 C B
      20% Aerated70°A3,4CB
Sodium Cyanide70°A3,4BC
Sodium Fluoride, 5% Solution70°B3,4CA
Sodium Hydroxide70°A3,4BB
Sodium Hydroxide, 5% Still  B3.4BB
Sodium NitrateFusedA3,4BA
Sodium Phosphate70°A3,4BB
Sodium Sulphate, 5% Still70°A3,4CA
      All Concentrations70°CCA
Sodium Sulphide, Saturated B3,4C 
Sodium Sulphite,5%70°A3,4CB
Sodium Thiosulphate    
      Saturated Solution70°A3,4CC
      Acid Fixing Bath (Hypo)70°A3,4CC
      25% Solution70° & BoilingA3,4CC
Sulphur, Moist70°B3,4CC
Sulphur Chloride (Dry) C3,4CA
Sulphur Dioxide Gas (Moist)70°B3,4CB
Gas (Dry)575°A3,4CA
Sulphuric Acid    
 Sulphurous Acid, Saturated 70° C C B
       Saturated- 60 lbs. Pressure 250° C C B
       Saturated-70-125 lbs. 310° C C B
      1442 lbs. Pressure375°CCB
Sulphurous Spray70°CCC
Tannic Acid70°ACA
 150°A A
Tartaric Acid, 10%70°ACA
Trichloracetic Acid70°CCB
Trichlorethylene (Dry)70°A4CA
      (Moist)   B
Water ABA
Zinc Chloride, 5% Still70°A3,4CC
Zinc Cyanide (Moist)70°AC 
Zinc Nitrate, SolutionHotAC 
Zinc Sulphate, 5%70°ACB

The media listed herein is considered to be  to pure at room temperature and unless otherwise specified dry. A change in condition can affect the ratings listed above. It should be noted that this reference table is only a partial listing for corrosion evaluation.

1. Erosion••••••••••••••••••••••••••••••••••••• subject to attack in the presence of H2So4.
2. Unstable••••••••••••••••••••••••••••••••••••• may cause explosive reaction.
3. Chloride Stress Corrosion Cracking••••••••••••••••••••• chlorides acting on anstenetic stainless steel (i.e. T-304 & T-321) can cause cracking in hose.
4. Pitting Corrosion••••••••••••••••••••••••••••• galvanic action can cause holes to form in hose (usually from acids when combined with air mixtures or when allowed to dry).