How to choose the correct pneumatic fitting
Choosing the correct Pneumatic Fitting Type for a particular application depends on several factors. These factors include:
- Tubing type needed ( Inch or Metric, Thermoplastic or Metal, Size)
- Air pressure or P.S.I. requirement
- Thread type of fitting needed (pipe, British pipe, metric, SAE Straight Thread)
- Vibration concerns
- Fitting material needed (brass, stainless steel, thermoplastic, nickel plated brass)
- Approvals needed (for example: Department of Transportation, Underwriters Laboratory, FDA)
Once these determinations have been made, there are a wide array of fitting types to choose from. What follows is a listing of the more popular styles available with a description of their uses. None of the following fittings are D.O.T. (Department of Transportation) approved.
COMPRESSION STYLE
Compression – Characteristics: No flaring or soldering needed. Tube compatibility: Available in inch dimension only, Copper, Aluminum, Thermoplastic; Thread availability: Male pipe , Female pipe; Body material: Brass; Approvals: UL listed for flammable liquid, SAE J-512 compliant.
Compress-Align – Characteristics: No flaring or soldering needed, preassembled fitting with captive sleeve. Tube compatibility: Available in inch dimension only, Copper, Aluminum, TFE, PEA, PFA, Thermoplastic; Thread availability: Male pipe, Female pipe; Body material: Brass; Approvals: None
Metru-Lok – Characteristics: One piece, preassembled fitting with captive ferrule; Tube compatibility: Available in metric dimension only, Copper, Aluminum, Thermoplastic; Thread availability: Male pipe, Female pipe, British parallel pipe, British tapered pipe, SAE Straight Thread, Metric; Body material: Brass; Approvals: None
Poly-Tite – Characteristics: A preassembled compact fitting. The exclusive acetal copolymer sleeve resists stress caused by compression; Tube compatibility: Available in inch dimension only, Thermoplastic and soft metal tubing; Thread availability: Male pipe, Female pipe; Body material: Brass or stainless steel; Approvals: None
Hi-Duty Flareless Tube Fittings – Preassembled fitting with a captive sleeve for high pressure applications (1000 to 4300 P.S.I.); Tube compatibility: Available in inch dimension only, Copper, Brass, Seamless Steel, Thermoplastic; Thread availability: Male pipe, Female pipe; Body material: Brass; Approvals: None
PUSH TO CONNECT STYLE
Prestolok Metal – Characteristics: One piece push to connect fitting for low pressure applications that allows for easy disassemble and reassemble. Come with a pre-applied thread sealant; Tube compatibility: Most Thermoplastic ( 85A Polyurethane excluded) in both inch and metric dimensions; Thread availability: Male pipe, Female pipe, British Parallel Pipe, British Tapered Pipe, Metric; Body material: Nickel Plated Brass; Approvals: None
Prestolok Composite – Characteristics: One piece push to connect fitting with glass reinforced black nylon body; Tube compatibility: Nylon Semi-rigid, Polyurethane, Nylon, Fluorpolymer, available in both inch and metric dimensions; Thread availability: Male pipe, Female pipe, British Parallel Pipe, British Tapered Pipe, Metric; Body material: Silicone free glass reinforced nylon; Approvals: None
PrestoWeld – Characteristics: Push to connect fittings that are weld splatter resistant and silicone free to meet the requirements of the robotic welding industry; Tube compatibility: Parker Microweld tubing; Thread availability: Male pipe, Female pipe, British Tapered Pipe; Body material: Nickel plated brass; Approvals: None
THERMOPLASTIC FITTINGS
True Seal – Characteristics: All plastic push to connect fittings manufactured from FDA compliant materials; Tube compatibility: Thermoplastic in inch dimension only; Thread availability: Male pipe, Female pipe, Barb; Body material: Acetal, Polypropylene, KYNAR; Approvals: FDA, NSF-51 for food contact, NSF-61 for drinking water.
Fast & Tite – Characteristics: Compression style all plastic FDA approved fitting; Tube compatibility: Thermoplastic, Glass, Soft Metal, available in inch dimension only; Thread availability: Male pipe, Female pipe; Body material: White Polypropylene, Black Polypropylene, White Nylon; Approvals: FDA, NS-51 for food contact.
Par-Barb – Characteristics: Injection molded fittings from high strength thermoplastic material; Tube compatibility: Vinyl, Polyurethane, Rubber Hose; Thread availability: Male pipe; Body material: Black High Density Polyethylene, White Nylon; Approvals: FDA, NS-51 for food contact.
BARBED FITTINGS
Dubl-Barb – Characteristics: Compact one piece, push on barbed fitting; Tube compatibility: Parker Polyethylene tubing; Thread compatibility: Male pipe, Female pipe, SAE Straight Thread; Body material: Brass; Approvals: None
Hose Barb – Characteristics: Manufactured in both regular hose barb and beaded hose barb styles; Tube compatibility: Rubber Hose, GPH Hose, hose clamps required; Thread availability: Male pipe, Female pipe, SAE Straight Thread, Metric; Body material: Brass; Approvals: None
Submitted by Roger Winchell