Will Schedule 40 Fittings Fit DWV Pipe?:
Schedule 40 Fittings:
Schedule 40 Fittings plumbing and piping systems. It is crucial to know the type of pipes and fittings utilized for every application. Most professionals and do-it-yourselfers will find that. At times, they are questioning whether or not Schedule 40 fittings will fit DWV pipes. Although both types are very common for residential and commercial plumbing. They serve different purposes and are built to perform under different conditions.
In this report, we’ll discuss the question of whether Schedule 40 fittings are compatible with DWV pipes. We will outline the differences, and explain what kind of problems may arise from the mix of these two components. And try to answer some of the most common questions surrounding the fitting of these two components together.
What is Schedule 40 Pipe?
Schedule 40 Fittings:
First of all, let’s discuss what Schedule 40 pipe is. Schedule 40 is a designation used for a type of pipe with an allowable wall thickness. The “schedule” number refers to the pipe’s pressure rating; where the higher the number, the thicker the walls and the more it can withstand. Schedule 40 pipes are made from materials such as PVC, CPVC, or steel.
For example, a Schedule 40 PVC pipe is a standard wall thickness that is generally. Acceptable for pressure and general-purpose plumbing applications. Such pipes are designed to endure only moderate pressure. But they are less rigid than more significant Schedule pipes. Such as Schedule 80, made for more demanding applications.
What is DWV Pipe?
Schedule 40 Fittings:
DWV stands for Drainage, Waste, and Vent. It is defined as the network of pipes used in domestic and commercial. Plumbing for the draining of wastewater and venting gas from sewer systems. DWV is mostly a PVC or ABS material. Used to make pipes for low-pressure waste and water flow in a system. They have not been designed for pressure servicing, unlike Schedule 40 pipes. Since DWV is gravity-based, so internal pressure is not substantially applied.
DWV piping materials, such as PVC or ABS. Have a thinner wall than Schedule 40 piping, and the fittings connected to the DWV system are developed to fit those thinner walls. The pipes typically have smooth interiors to allow the wastewater to flow easily with minimal friction. Traditionally, they are marked by the label “DWV” on the side of the pipe.
Can Schedule 40 Fittings Be Used on DWV Pipe?
Schedule 40 Fittings:
Schedule 40 fittings can be used on DWV pipe if the piping is the same type of material (PVC or ABS). However, there are a couple of significant caveats here. With some significant differences between the two systems that will be problematic if not anticipated and accounted for properly.
1. Material Compatibility
Both Schedule 40 and DWV pipes can be made of PVC, CPVC, or ABS. If you use PVC DWV pipe, then usually 40 PVC fittings will work for you. The same applies to ABS DWV pipes where scheduled 40 ABS fittings would be okay. The most critical factor here is that you use material both on the pipe. And fitting because you can not intermix PVC and ABS without a special adapter.
2. Difference in Wall Thickness
As you move from a DWV pipe to Schedule 40, the wall size is the thinner wall. For the most part, the standard thickness for DWV pipes is smaller than for Schedule 40. In simple terms, even though the OD of a Schedule 40 pipe is equal to or very close to one of a DWV pipe, the ID of the DWV pipe will be larger.
The wall thickness may vary with these two types, and that could result in a loose fit, especially if you are using fittings that are not marked as being compatible with DWV pipes. However, if you use Schedule 40 fittings for the same kind of material, they usually will fit over the DWV pipe although the wall of the DWV is thinner.
3. Differences in Fitting Design
Schedule 40 Fittings:
Schedule 40 fittings are typically for pressure applications, and they are put together with tighter tolerances to have a tight seal with good, pressure-tight integrity. The DWV fittings are constructed for low-pressure systems and not necessarily a tight seal like that of Schedule 40. Schedule 40 will physically fit over a DWV pipe, but the efficiency of the seal is likely compromised by this and will leak and/or operate improperly.
4. Glue and Solvent Cement
Both Schedule 40 and DWV pipes are usually glued or cemented with solvent cement, which chemically bonds the pipe and fits together. For Schedule 40 fittings and DWV pipes, solvent cement might be of the same formulation, but some manufacturers do offer variations based on whether one is working in a pressure system with Schedule 40 versus a drain system with DWV. Improper cement used can cause improper bonding that leads to failure in the joint.
Mixing Considerations for Schedule 40 Fittings and DWV Pipe:
Schedule 40 Fittings:
To consider using Schedule 40 fittings on DWV pipes, here are a few points to achieve a proper and soundly functioning installation.
1. Proper Fit
Whenever you connect a Schedule 40 fitting to a DWV pipe, make sure the fitting fits the pipe and is properly seated. Although the dimensions are the same, the variation in thickness might compromise the seal. You may need to use a specific fitting that fits the size of the DWV pipe, especially when that is a much more thinly walled pipe.
2. Use the Correct Cement
To start with, you will require taking or using solvent cement rated for the material and application: for PVC pipes, you should use PVC solvent cement, and find out whether the cement is compatible with both Schedule 40 fittings and DWV pipes.
3. Pressure Rating
Schedule 40 Fittings:
Even though the fittings and pipes appear to be the same size and material, note that DWV systems are only made to operate at a fraction of the pressures that Schedule 40 systems face. Thus, Schedule 40 fittings will be able to fit DWV pipes but are over-engineered for a system that does not require this level of durability.
4. Code Compliance
In many plumbing codes developed by the National Plumbing Code or the International Plumbing Code, depending on jurisdiction, there are specific requirements for which fittings and pipes to use in DWV systems. Therefore, using Schedule 40 fittings instead of DWV-specific fittings could violate local building codes or fail inspection in case the system is mandated to meet some sort of standard.
When To Use Schedule 40 Fittings with DWV Pipe:
Schedule 40 Fittings:
While most of the time DWV pipe is recommended for Schedule 40 fittings, there are certain instances when using these Schedule 40 fittings with DWV pipe will be justifiable, notably where:
- Aesthetic or structural reasons: You use Schedule 40 piping in other parts of your plumbing system and require uniformity in appearance or integrity in the material. Hence, you’ll opt to use schedule 40 fittings everywhere throughout the system to include DWV.
- Higher Strength Requirements: If your DWV system must be of higher strength for any reason completely as part of a system that is expected to experience significant physical stress and/or external pressure, for example, Schedule 40 fittings would provide you with more substantial durability than you might otherwise require in most DWV systems.
- Availability: In certain regions, Schedule 40 fittings may be easily accessible when DWV-specific fittings are not, so they can be substituted when needed.
FAQ’s:
Schedule 40 Fittings:
1. Can Schedule 40 PVC fittings be used on PVC DWV pipe?
Yes, typically Schedule 40 PVC fittings can be used with PVC DWV pipe with proper fit and the use of appropriate solvent cement.
2. How do the DWV pipe and Schedule 40 pipe differ?
DWV pipe has a lighter wall and is utilized in drainage systems, whereas Schedule 40 pipe has a thicker wall and is used to supply water at high pressures, such as water supply lines.
3. Can the fittings for Schedule 40 be used in a DWV system?
Yes, it is possible to use Schedule 40 fittings in DWV systems, and the foremost concern will be the difference in wall thickness and leakage issues. Be sure to check beforehand if the pipe and fitting are compatible with each other.
Conclusion:
Schedule 40 Fittings:
In a nutshell, Schedule 40 fittings can fit the DWV pipe, but there are quite several considerations involved, including differences in wall thickness, material compatibility, and proper methods of cementing. While Schedule 40 fittings will physically fit on most DWV pipes of the same material, they may not provide the best seal or performance for low-pressure drainage systems. Pipe and fitting materials must always match in a plumbing application and comply with the applicable standards of the manufacturers and local building codes.
