PVC vs Bronze
Looking to understand the work compatibility of PVC versus bronze pipe and fittings in what each is best suited for? Here, we will consider the details, specifications, similarities and dissimilarities between pipes and fittings made of either PVC or bronze. Understanding the key differences between plumbing material options can be vital to ensuring a successful, long lasting job and leak proof pipes.
There are various options available when it comes to pipes and fittings where the most common materials are PVC, CPVC, PEX, stainless steel, bronze, brass, PVDF, PE and polypropylene. No individual material alone will be suitable for every piping application and knowing some of the important properties, characteristics and differences between them can contribute to selecting the best plumbing material for the work at hand.
Comparing PVC and Bronze Plumbing
At first glance, one may consider bronze to be the stronger, more versatile material over PVC due to being a metallic alloy. However, modern synthetic materials such as PVC often have unexpected characteristics and performance abilities that can put them on par with or surpass the capabilities of metals. Of course, there are instances where metals far outweigh the ability of plastics such as PVC. These details and service preferences depend on the specific variables of the application, such as temperature, pressure, and chemical handling. The following eight points compare PVC versus bronze pipe and fittings:
1) Material of Manufacture & Appearance
PVC — PVC is a manmade, synthetic material known as a thermoplastic. PVC is short for polyvinyl chloride and is an inert, corrosion resistant material that does not rust and is less supportive of microbiological growth and algae. Many types of PVC are approved for handling potable water. As a material, PVC can be molded to a near limitless range of shapes and sizes, contributing to the many types of PVC plumbing sizes, lengths and fitting designs.
PVC is naturally opaque white in color. Pipes and fittings can have various colorant materials added to the base plastic resin prior to molding for the sake of producing color-coded plumbing.
Bronze — Bronze is a metallic alloy of copper and tin. It is both strong and malleable but is perhaps limited in its moldable range of fabrication sizes and options due to material requirements. As a metal, it is potentially susceptible to environmental corrosive effects, rusting and surface support of microorganism growth. Certain grades of bronze can contain elemental lead (either naturally or added) making it unsuited for potable water applications — to be approved, the alloy must be refined to lead-free standards as outlined by the Clean Water Act.
Bronze is a solid, muted gold color. Its properties as a metal differ from that of PVC and bronze is not capable of being molded into various colors.
2) Service Temperature Range
PVC — Temperature is a main application area where metals tend to outperform synthetic plastics. PVC is only rated to handle fluids up to 140°F (60°C) with a vicat softening temperature around 180°F (82°C). These temperature ratings mean not even hot water is suited for use within PVC plumbing and that PVC is best suited for ambient, stable temperature fluids and commodities.
PVC’s modulus of elasticity is affected as temperatures decrease, meaning the material’s ability to tolerate bending decreases. As temperatures near and reduce below 32°F (0°C), the brittleness of PVC also increases, making PVC plumbing more susceptible to cracking and fractures associated with impacts or bending stress. PVC does not tolerate freezing of the internal fluid contents and this scenario should be avoided.
Bronze — Similar to other metals, bronze has a relatively high maximum working temperature. Bronze is rated with a melting point of 1590°F (865°C) and often a max recommended service temp of 400°F (204°C) for continuous use. This makes bronze well suited for handling heated fluids and dissimilar from PVC. Also dissimilar to PVC, the structural integrity and brittleness of bronze does not increase with low temperatures and is not susceptible to the same freeze cracking concerns as PVC plumbing.
3) Internal Pressure Tolerance
PVC — PVC plumbing can be suited for internal fluid pressures up to 1230 PSI. This maximum rating applies to small diameter schedule 80 piping. In general, working pressures of PVC increase with increasing schedule rating and increase with decreasing piping diameters. In other words, as pipe size gets smaller, acceptable pressure ranges increase and as pipe sidewalls increase in thickness, acceptable pressure ranges also increase. For more on pipe schedule, consider our resource article Schedule 40 vs Schedule 80 Pipe & Fittings.
Bronze — Bronze, as a metal, has a relatively decent internal strength. However, total working pressure tolerance of bronze systems will depend on the strength of soldered joints and the specific grade / composition of the bronze material. At its maximum, bronze fittings can be rated to above 4,000 PSI but many times are rated on the lower end between 200 to 600 PSI. Similar to PVC — and a fact of plumbing — as piping interior diameter decreases, the acceptable pressure range increases, and as the thickness of the pipe wall increases, pressure tolerance will also increase.
Note: plumbing systems tolerance of pressure is directly dependent on the temperature maintained by the fluid being plumbed. As temperatures increase, acceptable pressure limits decrease. So named de-rating factors exist for calculating maximum service pressures based on service temperature.
4) Welding Method
PVC — PVC requires the use of specialized bonding cement that is unique to PVC and works only on PVC plumbing. The bonding cement is a solvent-based binder that effectively dissolves the outer layer of the PVC plumbing. This dissolving process causes joints to be chemically bonded / fused together to form a solitary piece. PVC pipe welding does not require an open flame or a soldering material, which many consider to be a benefit of the operation.
A potential drawback, if not properly and effectively performed, a sealed joint may not be formed and leaks can ensue.
Bronze — Bronze is welded similar to copper pipe and other metal plumbing. Also called braze welding, when welding bronze, a high heat flame and an additive material (solder) is used to simultaneously melt and fuse plumbing parts together to form a single piece of metal. The high heat and additive requirement of bronze welding can be considered a drawback in some plumbing connection scenarios such as within tight spaces or around sensitive materials.
Similar to PVC, if not professionally or properly performed, a leak-tight seal may not be completed.
5) Mechanical Strength
Definition: Pipe mechanical strength is a determination of the material’s resistance to impact cracking or breaking under stress loads.
PVC — PVC is defined as a rigid, semi-flexible material that can have plasticizers added to make it fully flexible. While still highly durable, PVC plumbing reports lower values for hardness and toughness than metal plumbing such as bronze. This means PVC equipment will be quicker to suffer damage from physical impact or to break versus bronze plumbing.
Bronze — Similar to stainless steel plumbing and brass fittings, bronze is a durable, rigid metal, and measurements / experiments that test its resilience indicate greater mechanical strength over PVC plastic.
6) Chemical Compatibility
PVC — People are sometimes surprised to learn PVC has fairly significant chemical resistance and compatibility and is often used for chemical applications. This is due to PVC's polymeric structure of packed hydrocarbons and the relative strength of halogen atoms by chemical nature; i.e. the chloride ions that make up PVC polyvinyl chloride. This is also why CPVC (chlorinated polyvinyl chloride) has greater chemical strength over PVC. In general, PVC is suitable for some common strong acids (such as hydrochloric and sulfuric acid), weak acids, many strong to weak bases, many brines, ionic solutions and some common alcohols and solvents. PVC is not recommended for many aromatic solvents, esters and ketones. For more on general chemical compatibility, review our Chemical Resistance Chart for PVC, CPVC, PVDF Pipe & Fittings.
Bronze — In general, bronze is not recommended for use with strong acids or strong bases but expresses decent compatibility with weak acids and caustics, common solvents and organics, ketones, esters, alcohols, oils including food and fuel oils, as well as salts or brines such as sea water and calcium chloride.
Specific chemical suitability of a piping material should always be verified with the manufacturer or supplier prior to use.
7) Insulation Properties
PVC — PVC is a synthetic, inert thermoplastic material that expresses excellent thermal and electrical insulation properties. The thermal coefficient of PVC’s heat exchange is relatively low, meaning there is an increased time requirement for thermal energy to transfer through the pipe material and affect the temperature of the internal fluid. This resistance to heat exchange occurs both ways, meaning the internal fluid if heated or cooled will resist releasing or absorbing external temperatures and an ambient fluid will resist being affected by differences in external temperatures.
Bronze — Metals, with bronze included, are considered excellent materials for conducting thermal and electrical energy. The elemental nature of bronze makes plumbing and equipment made from it fairly effective conductors of heat, more so than many grades of steel. Bronze plumbing will be quick to absorb and release heat based on internal and external temperature levels. This means thermal energy will be lost from bronze plumbing and fittings more quickly than plumbing made of PVC and the energy will need to be replaced more regularly to retain stable working temperatures.
8) Service Life & Cost
PVC — PVC as a plastic does not naturally break down and can often have a service life as long as or longer than its intended application. This is true only if the application does not cause degradation, affect the structural integrity or otherwise cause damage to the PVC material. Incompatible and semi-compatible chemicals as well as sunlight exposure can damage PVC over time and limit its service life.
Handling inert chemical fluids and water are best for maximizing PVC use. Uncoated PVC pipes and fittings are long term sensitive to sunlight ultraviolet (UV) damage and are not recommended for installation where exposure will occur. Painting or providing an insulating cover can shield PVC plumbing against sun damage and promote maximum service life.
PVC Cost — In terms of cost, PVC has one of the lowest prices per foot of currently-available plumbing materials. For fittings, PVC has one of the lowest costs per weight. Among synthetic and metallic plumbing materials, PVC is hard to beat in terms of its purchase cost and total cost effectiveness per service life.
Bronze — Metals have long been prized for their durable service use, and bronze plumbing is no different. However, differing from PVC pipes and fittings, bronze expresses a long term sensitivity to the corrosive effects of water. This is especially true whenever chlorides are present as in treated water, and can lead to eventual degradation, albeit after many years of successful service. Bronze does not have sensitivity to sunlight UV, and in situations of marked compatibility, the service life of bronze can outlast its application.
Bronze Cost — In terms of cost compared to PVC, bronze currently has greater price per weight and per size of bronze plumbing equipment.
Bottom Line: The service life of any material will be heavily dependent on the extent of environmental exposure, what chemical(s) if any it will handle and the structural stressors of operational temperature, pressure and fluctuations.
Takeaways | PVC vs Bronze Pipes and Fittings
In PVC versus bronze pipes and fittings, the comparison between a synthetic plastic and a refined metal alloy demonstrates many differences in terms of service, operation ranges, and cost. PVC is a lighter weight, man-made, low cost material that is versatile, flexible to semi-flexible and compatible with an appreciable range of chemicals. Bronze is a dense, fairly weighty metal alloy of copper and tin, increasing its cost and limiting its handling versatility and flexibility. Bronze exhibits corrosion resistance but can be slightly more susceptible than PVC to chemical effects along the metal’s surface. Bronze has high mechanical strength and is capable of providing long service within elevated temperatures and pressure stress.
Our review indicates PVC can outperform bronze within many modern plumbing scenarios and operations. Potable water handling is a key scenario where bronze must be specifically refined to lead-free grades to be considered compatible for use. If you are looking for top quality, top purity PVC plumbing produced from North America’s leading manufacturers that is ANSI / NSF certified -- we provide it. For more information about today’s different types of durable and versatile plastic piping, review our resource center. If you have any further questions, comments or plumbing needs, never hesitate to contact our expert team today -- with over 60 years experience, we are always ready to assist.