Water Valves: From The Roman Empire To Present Day
Back in the days, some elite Romans were already living in the 20th century. They had the privilege to enjoy the desired water flow and temperature of the bathtub, unlike most others of the time. They did so by building a diaphragm valve over a weir-like water reservoir. It was made up of leather, which operated manually. That crowned Romans with the tile of water valve inventors. With that, began the evolutionary era of water valves.
In this blog, we’ll tour retro water valves and their modern counterparts.
A Short Walk Through The History Of The Water Valve
Water has been the basic necessity for humans since day one. Finding ways to maintain its availability and quality has also been equally important. Ever since the formation of settlements and the beginning of agriculture, the need to have and control a required amount of water has become crucial for survival.
In quest of finding ways to facilitate cultivation, humans came across tons of water management methods and tools throughout history. Despite their completely transformed current forms, they have been quite effective in the past.
Before the Greeks and Romans, people used tree trunks and stones to control water flow. There isn’t much information about those times, except for the water clock by the Egyptians.
Advancement of Water Valves After Greeks and Romans
Greeks and Romans witnesses and efficiently contributed to the development of various hydraulic and mechanical tools and equipment, water valves being one of them. The primary revolution of the water valve is marked with that of the canal system, Romans discovered for irrigation.
Initially, valves were made with bronze due to its strength. These valves were designed to be attached to the pipes already fit in place. Despite a simple build, those valves did the job. They consisted of three parts: a hollow plug, a levy to turn the plug, and a support at the base of the plug.
These valves were found in large numbers from all over the Mediterranean, highlighting their significance at the time. Based on the evidence, primitive check and backflow valves have also been in use to keep clean water separate from the waste fluid –seems like we are not the only generation concerned with cleanliness. From the artifacts recovered from Augusta, it’s clear that the butterfly valve was quite common in the region.
Two other types of valves –flap and coin, also initiated in Ancient Rome. They were used to facilitate the force-water pumps. Plug cock valves were commonly found on main water lines that supplied water to the buildings. They worked as stop valves to control the water flow in various supply pipes. Traces of cock valve have also been found from the remains of the Palace of Tiberius that was built around 25AD.
These advancements were taken to the next during the renaissance when hydraulic machines became more common. Leonardo Da Vinci –the most famous polymath of his time, who also painted the Mona Lisa’s portrait, came up with several other practical valve designs and also made improvements to the existing ones.
Modern-Day Water Valves
Modern-day water valves that are much more convenient and effective have merely evolved on what Greeks and Romans left for us. As a matter of fact, we practically used the same plug cocked valve as the Romans until the 19th century. However, the category and type of water have widened to suit specific needs.
Things escalated quickly after the industrial revolution. Engineers introduced newer and more efficient valve designs. Moreover, the advancement of technology further aided in their development and betterment.
During the early 1800s, Timothy Hackworth, an eminent engineer, came up with the idea of using adjustable springs with steam safety valve. Previously, weights were used with these valves that did the work but were inefficient. Timothy’s innovation gained significant importance that the valve is now preserved and exhibited in London’s Science Museum.
Later in the early 20th century, P.K. Saunders, a mining engineer from South Africa decided to put his interest in archeology into work to meet his job requirements. He was entrusted with the responsibility of reducing power loss and leakage due to faulty valves. Considering Roman’s concept of diaphragm valves, Saunders came up with the modern diaphragm valve that was later adopted by most others.
Todays water valves can be threaded to, sweat, or even push in to.
A good example of how far valves have come, is Stream Products Inc's all in one Plumbing Boxes.
Modern Types Of Valves
· Ball Valve
A ball valve is based on a rotary ball and has a hollow center. With these valves, you can control the flow of water using the lever on top. One quarter-turn of the lever can open or block the way for the fluid to flow through. However, it is quite challenging to achieve a certain level of flow in between open and close, either a complete flow or no flow at all.
They are considered to be more lasting than most other types of valves. Ball valves are commonly found in large chemical, gas, and manufacturing industries, especially to control the flow of corrosive fluids.
There are four types of ball valves
Each of these types is further divided based on a number of variations like assembly, ball design, bore profiles, handles, etc.
· Butterfly Valve
The butterfly valve works on rotational motion. They are equipped with a hand-wheel, which is connected to the stem through a gearbox. The center of the stem features a flat disk that acts as the gate for the valve. Rotating the hand-wheel results in the opening and closing of the valve gate.
These valves are cost-effective and do not require a large space, which allows them to fit in smaller places as well. Moreover, they are easy to operate and maintain. However, they are the fastest neither do they ease flow management.
Butterfly valves are found at services like high-pressure water service, high-temperature fluid management, vacuum services, controlling slurry fluids, etc.
· Check Valve
Check valves are designed to facilitate the flow of liquids and gases in one direction. They feature two ports, an input port, and an output port. Since the fluid is only allowed to flow in a specific direction, the valve is also called a ‘one-way valve’ or ‘non-return valve’.
A check valve works on the principle of differential pressure. It requires higher pressure at the input port than the output. If in any case the pressure increases at the output or decreases at the input port, the valve automatically closes, protecting the whole internal system. Their unaided shutting off function stands to be their strongest point as they do not need a human to control them. However, the closure mechanism does not work the same way for each check valve type.
· Faucet Valve
Faucet valves are the common tap found in bathrooms and kitchens used to control water flow and its temperature. They are largely divided on the basis of knob they feature. Some have one knob to control both hot and cold water while others have two separate knobs designated to hot and cold water.
These knobs effectively seal the faucet to reduce the chances of leakage. However, some of the faucet valves require frequent maintenance.
· Gate Valve
Gate valves are designed to cease the flow of fluid by isolating pipelines with a gate-like disc. They are used to fully allow or restrict the flow, but not to regulate it. They hardly make any difference in pressure when the gates are opened, ensuring smooth and uninterrupted flow.
Gate valves consist of a disc, a screw-based stem, and a hand-wheel to operate. One clockwise turn of the hand-wheel can either be to or close the flow. When the valve is closed, the disc is lowered, resting in the path of the flow against the two openings. To resume the flow, the hand-wheel is turned in the opposite direction, which lifts the disc, giving a free way to the fluid. Due to their straightforward and limited-sized construction, they are mainly used with large underground and above-ground pipes.
These valves are not the quickest to operate because moving the threaded stem up and down takes time. However, it prevents leak and pressure drop.
· Globe Valve
Globe valve also known as the throttling valve is one of the most common types of water valves. They are designed to allow, restrict, and control the flow. However, the pressure drop with this type of valve is quite high.
It consists of a threaded stem, a disc, and a hand-wheel. To reach the desired fluid-flow, the threaded stem has to move a certain distance upward or downward. When the hand-wheel is entirely down the disc is settled over the seat of the valve, which completely cuts the flow.
Since the stem does not have to cover a large area to reach the desired position, it makes this valve quick to work with. However, frequent contact of the seat and the disc might require periodic repair.
· Pressure Relief Valve
A pressure relief valve also referred to as a safety valve is a device to maintain pressure in the pipes or vessels, preventing the system from catastrophes due to extreme pressure. In a situation where the fluid pressure goes beyond the limits of the system, there can be massive destruction. Since electric-powered or human-controlled systems fail in such a situation, a pressure relief valve is what comes in handy.
Being an automatic valve, the pressure relief valve is in action at all times. They vent the extra fluid through the designated openings to reduce pressure in the vessels.
· Supply-Stop Valve
Supply-stop or shutoff valves are one of the most common types of valves. They are mainly used in house plumbing to control the flow of water from the main water line. They are available in different materials –iron, copper, and CVPC and build like straight, angled, quarter turn, or multi-turn.
Shut-off valves are pretty simple and quick. Due to their compact size and easy installation they can be stationed at compact places quite easily. Moreover, they are inexpensive and convenient to operate.
· Pinch Valve
The pinch valve is a dual opening valve with a full bore in the center. This type of valve utilizes ceases water flow through the pinching effect of a rubber seal. These pressure-operated valves can be used to allow, obstruct, or control the flow of water in the pipes.
The pinch valve is lined with rubber seals, facing each other that clamp tightly together to obstruct the water flow. The use of rubber makes this valve last longer than others, hence they do not need frequent repairs.
This type of valve works great with a variety of fluids, thereby are commonly found in industries. Plus, they are quite inexpensive and easy to install and operate.
· Diaphragm Valve
Diaphragm valves are a type of throttle valve that works similar to pinch valves. They control the water flow with the help of a thin membrane positioned at their entrance and exit. The flexible membrane exerts a force on the valve to open or obstruct the opening, which allows for extensive control of water flow.
These valves are leak-proof and quick to function. Although they are available in different materials, they usually do not require frequent repairs. However, they are limited to lower to moderate temperature and pressure applications.
· Plug Valve
A plug valve is a manual valve featuring a cylindrical plug that cuts down the water flow. When the valve is opened, the plug is lifted from the bottom, creating a free passage for the water to flow. However, when it’s turned to a closed position, the plug blocks the pipe, which stops the flow.
Plug valves can be used to open, close, or control the flow of water. These can be two to three-way valves that divert or combine water from one or more sources. The usually used in low-pressure vessels, but some designs also facilitate higher pressure. Despite their leak-proof and easy to maintain build, they might not be much favored over a ball valve due to higher prices.
Hope this article would have been informative for you. The discovery and initial use of this simple device are rooted in Ancient Rome, but it has come a long way. Today we find a variety of water valves available at a mere cost. However, their importance has only increased over time.