LP fitting O rings

I’ve got a sunflower Mr. Heater, a weed burner and a grille hose that the O ring has broken or looks like it should be replaced. I stopped by Ferrellgas plant and asked the guy what to use. He told me he didn’t know. Not sure if they are anything special, or just match it up at the hardware store. I actually have an assortment of blue ones from doing A/C work. Stopped by True Value that has a huge grilling department. They weren’t much help either. Good friends brother-in-law lost almost enough hide to kill him in a grille leak explosion. Found some on Amazon. But no way to compare size. Anybody been there, done that??

I just match them up

Due to many applications, there is also a wide variety of O-ring material choices available. One MUST determine what material any individual “o”ring is made of and decide if that material is suitable for the application.
Factors to Consider When Picking O-rings
When picking the right O-ring for your specific application, there are many factors to consider. They include but are not limited to operating conditions, chemical compatibility, sealing pressure, temperature, durometer, size, and cost. Depending on the specific situation, you may also look at abrasion, tear, ozone, electrical resistance properties. Additionally, you can perform appropriate field tests to ensure the fluid, temperature, pressure, and environmental conditions are compatible with the O-ring of your choice.
O-ring Material Selection Guide
In order to accommodate a large variety of applications, manufacturers make O-rings and seals using various elastomers with different physical and chemical properties. Let’s look at some of them below:

Nitrile Butadiene Rubber (NBR)
Resistant to: Water, Petroleum Oils & Fluids, and Hydraulic Fluids

Not recommended for: Phosphate ester base hydraulic fluids, automotive brake fluids, ketones, strong acids, ozone, freons, halogenated hydrocarbons, and methanol

Temperature Range: -40° to +250°F, although that’s an average for the lower and upper tolerances for the various nitrile butadiene rubber (NBR) compounds manufactured by Parker. Parker’s Buna-N compound, which ranges from 70 to 90 durometer hardness nitrile, withstands temperatures from -30°F up to 250°F which includes compounds N0674

Hardness: 40 to 90 durometers Shore A
Buna Nitrile
Most popular elastomer O-ring material. Parker Hannifin uses 70 durometer hard nitrile (Buna-N) for most of its standard O-rings supplied, with 90 durometer available for tube fittings and adapters. Seal professionals value Buna-Nitrile elastomer for competitive price and excellent resistance properties to petroleum-based oils and fuels, silicone greases, hydraulic fluids, water, and alcohols.

Ethylene-Propylene (EPDM)
EPDM has a spotless reputation in the sealing world because of its excellent resistance to heat, water and steam, alkali, mild acidic and oxygenated solvents, ozone, and sunlight (UV). Nevertheless, experts do not recommend EPDM compounds for gasoline, petroleum oil and grease, and hydrocarbon environments.

Resistant to: Extreme cold, steam, hot water, sunlight and UV, dilute acids, ketones, alkalis

Not recommended for: Petroleum base oils and di-ester base lubricants

Temperature Range: -65° to +450°F

Hardness Range: 40 to 90 durometers Shore A
Neoprene (CR)
Neoprene is a general-purpose elastomer with moderate resistance properties to petroleum oils and weather (ozone, sunlight, UV, and oxygen). Neoprene O-rings have a relatively low compression set, good resilience, abrasion, and are flex cracking resistant.

Resistant to: Refrigerants (freons, ammonia), high aniline point petroleum oils, mild acids, and silicate ester lubricants

Not recommended for: Phosphate ester fluids and ketones

Temperature Range: -45° to +250°F

Hardness: 50 to 80 durometers Shore A

Fluorocarbon (Viton)
When we talk about fluorocarbon O-rings, Viton is a popular trade name that may come into your mind. Fluorocarbon (FKM) compounds combine high-temperature resistance with excellent chemical resistance. These properties make them a popular choice for many applications, including aircraft and automotive industries.

Resistant to: Petroleum base oils and fluids, some phosphate ester base fluids, silicone and silicate ester base lubricants, acids and halogenated hydrocarbons
Temperature Range: Standards -15°F to +400°F, but some Parker FKM Viton compounds can tolerate temperatures down to –65F and up to +450F.

Hardness: 50-95 Durometers Shore A

Perfluoroelastomers (FFKM) (Parfluor)
Perfluoroelastomers (FFKM) are an extension of the Fluorocarbon FKM elastomers extending the compatibilities of the FKM while at the same time extending the upper temperature limits of the materials while compromising the lower temp limits. FFKMs are the cleanest/purest compounds available on the market. They are the first choice for clean applications and are particularly popular in the semiconductor industry.

Silicone
Silicone O-rings have many outstanding properties, including excellent flexibility and fatigue life, strong ozone, and UV radiation resistance. Despite the abovementioned characteristics, experts do not recommend silicone O-rings for dynamic applications. The low strength and poor abrasion resistance as well as high gas permeability, make them not compatible with the most petroleum fluids, ketones, water, and steam.

Resistant to: Dry heat (air to 400°F) and high aniline point oils

Not recommended for: Most petroleum fluids, ketones, water and steam

Temperature Range: -175F to +450°F

Hardness: 40-80 Durometers Shore A

Polytetrafluoroethylene (PTFE)
Polytetrafluoroethylene (PTFE) O-rings are designed to be used in harsh environments with temperatures ranging from -450°F to 600°F. PTFE O-rings are compatible with the widest range of chemicals, such as acetone, isopropyl, methyl, etc. Furthermore, they have low gas permeability and low absorption. Unfortunately, due to polytetrafluoroethylene material properties, pure PTFE O-rings are very rigid and hard to apply. Therefore, manufacturers, including Parker, solve this problem by mixing PTFE material with various fillers to provide users with more flexibility. PTFE seals are often used in food, pharmaceutical, and medical industries.

Resistant to: Most chemicals, excluding alkali metals, fluorine, a few fluoro-chemicals such as chlorine tri-fluoride and oxygen difluoride

Not recommended for: Applications requiring O-Ring stretch and compression

Temperature Range: -260°F to 300°F

Hardness: 55 to 60 durometer Shore D

Replaced mine with one from a faucet o ring kit. Was it the right one? No idea but it worked. So far.

Mr Heater has o rings. I bought a half dozen when they ran a sale last Xmas. I tried the faucet rings and they didn’t last.

A lot of hardware stores have the correct one marked in their o-ring area. I know my Ace Hardware does and also the Hardware Hank by the hunting land.
DT

I googled Mr. Heater o ring. Ebay has a 100 pack, that seem like a few too many. Looks like Tractor supply is supposed to stock 20 pk for $4.99. I’ll check them out next time I go that way. BTW, they say they are neoprene. After seeing my buddies brother-in-law. I would don’t want to mess with kinda like it.

Huntindave wrote:

Due to many applications, there is also a wide variety of O-ring material choices available. One MUST determine what material any individual “o”ring is made of and decide if that material is suitable for the application.
Factors to Consider When Picking O-rings
When picking the right O-ring for your specific application, there are many factors to consider. They include but are not limited to operating conditions, chemical compatibility, sealing pressure, temperature, durometer, size, and cost. Depending on the specific situation, you may also look at abrasion, tear, ozone, electrical resistance properties. Additionally, you can perform appropriate field tests to ensure the fluid, temperature, pressure, and environmental conditions are compatible with the O-ring of your choice.
O-ring Material Selection Guide
In order to accommodate a large variety of applications, manufacturers make O-rings and seals using various elastomers with different physical and chemical properties. Let’s look at some of them below:

Nitrile Butadiene Rubber (NBR)
Resistant to: Water, Petroleum Oils & Fluids, and Hydraulic Fluids

Not recommended for: Phosphate ester base hydraulic fluids, automotive brake fluids, ketones, strong acids, ozone, freons, halogenated hydrocarbons, and methanol

Temperature Range: -40° to +250°F, although that’s an average for the lower and upper tolerances for the various nitrile butadiene rubber (NBR) compounds manufactured by Parker. Parker’s Buna-N compound, which ranges from 70 to 90 durometer hardness nitrile, withstands temperatures from -30°F up to 250°F which includes compounds N0674

Hardness: 40 to 90 durometers Shore A
Buna Nitrile
Most popular elastomer O-ring material. Parker Hannifin uses 70 durometer hard nitrile (Buna-N) for most of its standard O-rings supplied, with 90 durometer available for tube fittings and adapters. Seal professionals value Buna-Nitrile elastomer for competitive price and excellent resistance properties to petroleum-based oils and fuels, silicone greases, hydraulic fluids, water, and alcohols.

Ethylene-Propylene (EPDM)
EPDM has a spotless reputation in the sealing world because of its excellent resistance to heat, water and steam, alkali, mild acidic and oxygenated solvents, ozone, and sunlight (UV). Nevertheless, experts do not recommend EPDM compounds for gasoline, petroleum oil and grease, and hydrocarbon environments.

Resistant to: Extreme cold, steam, hot water, sunlight and UV, dilute acids, ketones, alkalis

Not recommended for: Petroleum base oils and di-ester base lubricants

Temperature Range: -65° to +450°F

Hardness Range: 40 to 90 durometers Shore A
Neoprene (CR)
Neoprene is a general-purpose elastomer with moderate resistance properties to petroleum oils and weather (ozone, sunlight, UV, and oxygen). Neoprene O-rings have a relatively low compression set, good resilience, abrasion, and are flex cracking resistant.

Resistant to: Refrigerants (freons, ammonia), high aniline point petroleum oils, mild acids, and silicate ester lubricants

Not recommended for: Phosphate ester fluids and ketones

Temperature Range: -45° to +250°F

Hardness: 50 to 80 durometers Shore A

Fluorocarbon (Viton)
When we talk about fluorocarbon O-rings, Viton is a popular trade name that may come into your mind. Fluorocarbon (FKM) compounds combine high-temperature resistance with excellent chemical resistance. These properties make them a popular choice for many applications, including aircraft and automotive industries.

Resistant to: Petroleum base oils and fluids, some phosphate ester base fluids, silicone and silicate ester base lubricants, acids and halogenated hydrocarbons
Temperature Range: Standards -15°F to +400°F, but some Parker FKM Viton compounds can tolerate temperatures down to –65F and up to +450F.

Hardness: 50-95 Durometers Shore A

Perfluoroelastomers (FFKM) (Parfluor)
Perfluoroelastomers (FFKM) are an extension of the Fluorocarbon FKM elastomers extending the compatibilities of the FKM while at the same time extending the upper temperature limits of the materials while compromising the lower temp limits. FFKMs are the cleanest/purest compounds available on the market. They are the first choice for clean applications and are particularly popular in the semiconductor industry.

Silicone
Silicone O-rings have many outstanding properties, including excellent flexibility and fatigue life, strong ozone, and UV radiation resistance. Despite the abovementioned characteristics, experts do not recommend silicone O-rings for dynamic applications. The low strength and poor abrasion resistance as well as high gas permeability, make them not compatible with the most petroleum fluids, ketones, water, and steam.

Resistant to: Dry heat (air to 400°F) and high aniline point oils

Not recommended for: Most petroleum fluids, ketones, water and steam

Temperature Range: -175F to +450°F

Hardness: 40-80 Durometers Shore A

Polytetrafluoroethylene (PTFE)
Polytetrafluoroethylene (PTFE) O-rings are designed to be used in harsh environments with temperatures ranging from -450°F to 600°F. PTFE O-rings are compatible with the widest range of chemicals, such as acetone, isopropyl, methyl, etc. Furthermore, they have low gas permeability and low absorption. Unfortunately, due to polytetrafluoroethylene material properties, pure PTFE O-rings are very rigid and hard to apply. Therefore, manufacturers, including Parker, solve this problem by mixing PTFE material with various fillers to provide users with more flexibility. PTFE seals are often used in food, pharmaceutical, and medical industries.

Resistant to: Most chemicals, excluding alkali metals, fluorine, a few fluoro-chemicals such as chlorine tri-fluoride and oxygen difluoride

Not recommended for: Applications requiring O-Ring stretch and compression

Temperature Range: -260°F to 300°F

Hardness: 55 to 60 durometer Shore D

OH That makes it a lot easier But tks for the info.

Terry Heese wrote:

OH That makes it a lot easier But tks for the info.

Your welcome. I would have just posted the link to that info, but for whatever reason, that option was not working. Better for some one to make an informed purchase when dealing with LP gas, than to just guess and hope they are buying the right O-ring.

As was mentioned above, all too often, even the folks in the various retail outlets don’t have a clue either, so they are of little help.

Try Mikes LP in Maplewood