Can You Use Push-Fit Fittings Underground?

Can You Use Push-Fit Fittings Underground?

Push-fit fittings are designed for pushing together to form a seal.

They boast plumbing usage, providing an inexpensive and quick method of adding extra items, such as bathroom fixtures or kitchen faucets, without needing glue or soldering.

Yes! Flexible push-fit fittings are best suited for underground water services. The fittings accommodate several installation options, including direct burial without using conduit, side-by-side installation in PVC pipe, and immediate burial in PVC pipe.

You should consider several factors when installing underground push-fit fittings to ensure that the fittings can deliver optimum performance in the application:

1. The Type of Fitting

For long pipe runs, you should consider G1, G2, and G3 fittings. G3 is the most commonly used push-fit fitting. G2 and G3 fittings have greater strength and durability than the G1 fitting.

2. The Application

You should also consider the type of water service you are installing, for example, potable water, wastewater, fire protection, or process transfer.

Each application has unique characteristics that require a specific design to ensure optimum performance.

3. The Surrounding Environment

The temperature and materials you use to construct the pipeline system can significantly impact the fittings’ design.

You should consider using polypropylene or polyethylene fittings when there are high temperatures, moisture, or corrosive chemicals in the pipe work.

4. The Design Pressure and Flow

The fitting size you use is essential for underground water services. You should size fittings to provide sufficient flow capacity for the application.

Using oversized fittings can result in wasted space and excessive pressure drops. At the same time, undersized fittings can result in lower-than-required flow rates and water hammer conditions.

Why Do Push-To-Connect Fittings Leak?

Here is why you should switch to push-to-connect fittings so you never have this problem again!

1. To Maintain Proper Water Pressure

Leaks can cause a drastic decrease in water pressure. As the pipe gets larger, the pressure decreases because there is more distance between your tap and the end of the pipe.

So, if you have a push to connect the fitting, and it leaks, water pressure will remain near your tap for months.

With pop-offs, the pressure drops much faster to get leak alerts immediately. If you do not connect pop-offs properly, water pressure reduces dramatically. This leads to expensive repairs and more water damage.

2. To Avoid Cross Connection

Switches in the water system often cause the water to turn off at one of your fixtures.

This can cause the pop-off fitting to push out of the leak location prematurely and then into another location, possibly a wall or a drop ceiling.

3. To Prevent Water Damage

The main reason you should refrain from having leaks is that they can cause damage.

Not only do they reduce water pressure, but they also make your home more susceptible to mold and mildew damage. If you have a huge leak, it can cause flooding damage.

Pipes are exposed to many chemicals and corrosion in the water, so you need to replace them every 20 to 30 years if they are exposed to a lot of water. 

If you switch to push-to-connect fittings and have them installed professionally, you will see a minimal risk of damage. 

4. To Prevent Structural Damage

Some of the larger leaks are the result of structural damage. You may have a main water leak in your crawl space or attic or through your floor; This can cause damage to your home.

5. To Reduce Your Overall Utility Costs

Leaks can use up a lot of water and energy, so it’s also essential to reduce your demand on the system by replacing leaking fittings with push-to-connect versions so that you save water and energy. 

No-Hub Vs. Shielded Coupling

Factor	No-Hub	Shielded Coupling
Material	Made from 304 Stainless Steel	Consist of a flexible elastomeric sealing sleeve, a protecting and supporting continuous metal shield or shear ring, and metal screw clamping bands.
Installation	You can install underground or above ground	Underground applications, but can be used above-ground where the user sees fit.
Sealing	Used for joining cast iron pipe sections with a flexible seal.	Designed for a greater sealing force on corrugated pipe.
Size	Available in 1-1/2” through 15”, 2” x 1-1/2”, 3”x2”, 4”x 2”, and 4”x 3” sizes.	Available in sizes from10″ to 60.”
Flexibility	Used for joining cast iron pipe sections with a flexible seal.	It has Stainless steel shielded elastomeric gasket ensures the flexibility.
Price	Costs $17.95	Costs $19.99.

Can You Use a No-Hub Coupling on The ABS Pipe?

Yes! You can use ABS piping to:

1. Repair PVC And ABS Piping Too

You can use a compression hub coupling on ABS piping; however, a no-hub coupling is recommended.

The no-hub coupling is more durable because the socket will be in constant contact with the pipe wall and reduce the chance of scratching or cutting the pipe.

2. Replace Galvanized Steel and Copper Piping

If you are replacing galvanized steel or copper pipes, you can use ABS pipes to replace.

3. Create New Pipes from Standard Fittings

There are no restrictions in using ABS piping for new construction as long as you use the correct fittings.

You can use standard fittings when connecting the pipe to a hub coupling or another with a compression hub coupling.

You can also cut the end of the pipe for a start and use standard fittings to make the back smooth.

4. Use in Place of ABS Pipe

ABS pipe is not as flexible as ABS plastic tubing; after time, it may crack from expansion, cracking, vibration, abuse, or installation errors.

When you cannot repair or replace an existing section of ABS piping and need to use it instead of regular piping, use rigid-flex coiled tubing (RFT).

5. Provide an Easy Transition Between Copper and Plastic

If you are installing copper pipes in an area with an ABS pipe, you can use a compression hub coupling to connect the copper and plastic pipes.

The intermediate pipe will have a hub well to hold the copper and plastic pipes together.

Are Compression Fittings Better Than Push-Fit?

It depends on the specific application.

Factor	Compression Fittings	Push-Fit
PSI Rating	They can handle higher pressures than push fittings. They rely on a tightened nut and washer to form a seal.	They use a rubber O-ring that may not withstand higher pressures.
Clarity Of Water	Higher-quality water will flow more easily through compression fittings	They may allow more debris into the tubing, causing cloudiness in the water.
Leveling Of Tanks	You can disassemble and reassemble compression fittings without the worry of leakage.	It is not recommended because they may cause a leak.
Length Of Tubing	They will allow up to 10 meters of tubing.	It is often limited to 1 or 2 meters in length because the rubber 0-ring may lose structural integrity over long periods at high pressures.
Price	They are cheaper, often costing around $2 to $3 per piece	They can cost up to $10 per piece.
Flowrate	Can handle up to 10 liters per minute.	They are often limited to 2 or 3 liters per minute due to the high pressure required for compression.

How Much Pressure Can a No-Hub Coupling Hold?

Type	Pressure it can hold
Standard No-Hub Coupling	20 Psi for 1 ½” – 5”, 18 Psi for 6”, 10 psi for 8”, 6 Psi for 10”, 12”, and 15”.
Heavy-Duty No-Hub Coupling	500 PSI
Shielded No-Hub Coupling	1500 PSI
Adjustable No-Hub Coupling	43 PSI
Reinforced No-Hub Coupling	18 PSI
Flexible No-Hub Coupling	43 PSI

Can You Mix PVC And ABS Plumbing?

No! I do not recommend joining and using ABS and PVC within the same piping system.

This is because the dissimilar materials will cause a galvanic reaction resulting in the breakdown of one or both materials.

This process forms a chemical compound that produces heat and hydrogen sulfide gas, which is toxic.

Yet you can use copper piping for PVC-to-PVC joints and brass for ABS-to-ABS joints, as both metals are resistant to the corrosion effects of sulfuric acid.

On the other hand, you can join ABS plastic to polyvinyl chloride (PVC) piping in several ways.

The most common is the combination of a steel braided polyvinyl chloride (PVC) hose with an ABS fitting and strain relief coupling.

When joining an ABS pipe to a PVC pipe, the plastic joint consists of an ABS fitting with a flange and a PVC pipe threaded on the end with a flexible coupling that fits into the hole in the ABS fitting.

The coupling is fastened using two screws.

Another way to join ABS plastic plumbing is to use an inner liner made of rigid plastic such as high-density polyethylene or polyvinyl chloride (PVC). The liner is inserted into an ABS coupling.

The interior of the liner is roughened on one side, which gives it a grip against the ABS fitting.

The roughness of the PVC lining provides a surface for the glue to adhere to for a watertight seal between the two pipes.

Another way to join ABS pipe and PVC pipe is to use an ABS liner you glue into an ABS fitting and then use a PVC pipe inserted in it. The liner is secured inside the ABS fitting using a vacuum fit coupling.

Can You Use Rigid Compression Couplings Underground?

Yes!

Here is how you can use rigid compression couplings underground:

1. Install the couplings in a pre-drilled, unbonded depth.

2. Install the couplings on an open-hole drill rig with a shoulder-to-shoulder pattern and grout between each coupling.

3. Use red thread to tie off the threads of each coupling, then wrap them around green threaded rods.

4. Use an excavator to backfill, then grout between the couplings.

5. Install a grout curtain, which prevents water from entering the well workings during flooding or securing loose equipment, and then fill the well with water.

This will create pressure equal to that at the surface while grouting around each coupling.

However, it is essential to remember that removing a coupling is only possible if you have the correct equipment on hand. You must use thread rods and an armature bar to remove a coupling.

5/8″ couplings have a nut with a 3.75″ outside diameter, which requires a specially designed nut spinner to remove it from the armature bar.

Each coupling also has a different locking feature, meaning you must remove the couplings in ascending order.

If a coupling is installed out of order, you can still remove it, but you must first use a coupling wrench to loosen it from its neighboring couplings.

Couplings also require a specific amount of torque to install or secure them while they are still in the well. A torque wrench is necessary to tighten them before they are placed underground.

What Are No-Hub Fittings Used For?

Use	Explanation
Connecting Cast Iron Pipes In Drainage Systems	They connect cast iron pipes in drainage systems to reduce the amount of pipe that needs to be passed by a valve.
Joining PVC Or ABS Pipes In Waste And Vent Lines	You can use the no-hub fitting to join two pipe sections with different diameters. A no-hub fitting effectively converts a larger-diameter pipe into a smaller one by reducing the inside diameter of the smaller pipe. This is important when joining pipes before they are connected to fittings, such as in waste and vent lines.
Connecting Pipes of Different Materials, Such as Cast Iron To PVC	They cast iron pipes with varying diameters to a single PVC pipe. This is important when you cannot join two pipes with a coupling, such as when the pipe is cast iron and has hub dimensions of 1000mm or more.
Creating A Watertight Seal in Plumbing Systems	They create a watertight seal in plumbing systems when joining plastic pipe to cast iron. You can clamp the cast iron pipe into the fitting and soldering or cement the joint.
Replacing Damaged or Corroded Fittings In Existing Systems	They can replace damaged or corroded fittings in existing systems. You can replace these fittings with an original fitting that is still working or with a new no-hub fitting.
Creating A Watertight Seal in Drainage Systems	Drain contractors use the no-hub fitting to create a watertight seal between two cast iron pipes when installing a clean-out at the bottom of a drain.

Which Fittings Are Not Approved for Drainage?

Fittings	Reason
Pipe Elbows with A Sharp 90-Degree Angle	Using 90° elbows upstream of a pump inlet can distort the approach flow. Resulting in spatial and temporal velocity variations and swirling flow that negatively affects pump performance and increases maintenance requirements.
Tee Fittings with A Branch Outlet Less Than 1 1/4 Inches in Diameter	A size reduction would create an obstruction to flow, possibly resulting in a backup of flow. An interruption of service in the drainage systems, or a stoppage in the pipe.
S-Traps	It is because the “S” trap will siphon or suck water out from the trap, which will end up releasing methane (sewer) gases into the home.
Compression Fittings	They are bulkier and can be considered less aesthetically pleasing compared to the soldered joint. They are not nearly as robust as soldered fittings, making them much more sensitive to powerful stresses.
Double Sanitary Tees	You cannot use them for connections to fixtures and appliances with pumping action because it has a short pattern for change of direction.

Conclusion

Push-fit fittings are more economical than threaded fittings and provide a simple and fast installation method.

In addition, they are easier to disassemble than threaded fittings. These fittings are commonly used for a pipe to pipe and pipe-to-valve connections for typical household plumbing applications.