This is a simple system in which each fixture has its own vent pipe. It is simple to plan and implement, because you won't have to worry about placing different fixtures close enough together or using pipes big enough for multiple fixtures. Each vent is a small, isolated pipe that you can work with separately. However, having a different vent pipe for each fixture will mean that you have a lot of vent pipes running up through your building and out your roof. This uses a lot of unnecessary piping, and you'll be doing more work than you need to. Depending on the fixture, the vent pipe can be fairly small but should be positioned within a couple feet of the fixture. Make sure to check your local building codes for specific regulations about sizes and distances for your vent pipe. A common layout is to have a drain pipe run horizontally away from a sink or other fixture for up to two feet. Then the drain pipe will join with a vertical pipe. Down from the joint, this vertical pipe acts as a drain for the fixture. Up from the joint, it vents the fixture. Usually, the vent pipe must extend six inches above the roof or 12 inches (30.5 cm) away from vertical walls, but double check your building codes and requirements to make sure. Make sure every fixture has a vent pipe associated with it so that your whole plumbing system will run quickly, smoothly, and safely. Vent stacks can run parallel with waste pipes to ensure proper ventilation in tall buildings. Sub-vents may be branched together to exit 1 vent stack, allowing for only 1 hole in the roof for ventilation.
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One-sentence summary -- Understand dry venting. Create a dry vent by attaching a ventilation pipe to a fixture's drain pipe. Extend the vent pipe outside the building according to building regulations. Repeat the ventilation process with any other fixtures you're installing. Vertical ventilation pipes called vent stacks provide air circulation to any part of the plumbing system.

Q: Designed to allow passengers to view the water below them, the boats often tour reefs, shipwrecks, or other hotbeds of aquatic activity. Tours on these boats can be relatively affordable in comparison to other underwater exploration methods, and operate in many coastal cities and natural springs. While this isn't a repeatable option for most (outside of buying a DVD of The Hunt for Red October) seeing as personal luxury subs start at around $600,000, both military and civilian submersible vehicles routinely patrol and investigate the briny depths.  Tours of non-operational military subs are possible for a window into that underwater world, however, and companies in vacation destinations often offer submarine trips to tourists. When discussing submersible platforms, HOVs are human operated vehicles, and ROVs are remotely operated vehicles. The National Oceanic and Atmospheric Administration's website contains information detailing multiple submersibles researchers use today (both HOV and ROV), including a model named “Alvin” that's been in use since 1964! Combing the shoreline for seashells, sand dollars, and sharks' teeth allows us a unique, surface-dweller's peek under the sea. It's a little eerie when you think about it, considering the majority of what washes up is dead or dying, but humanity has learned much of the sea by what's washed ashore. Indeed, until the last century, that's how we gathered most of our knowledge about the ocean.  A living, adult giant squid wasn't even able to be photographed until 2012. We only knew of its existence by pieces of the squid that became stranded on the beach, or by finding them in the bellies of sperm whales that themselves had washed ashore.  (As stirring as it may be, anecdotal evidence presented by ancient mariners is, unfortunately, not considered proof.) Strolls along the beach anywhere can yield once-in-a-lifetime encounters with the unfamiliar. Residents of Oxnard, California, along with other cities along North America's pacific coast were acquainted with a sea creature entirely unknown to them (and to most people) when mass quantities of by-the-wind sailors (scientific name: Velella velella) were deposited on their beaches.
A: Ride in a glass-bottom boat. Board a submarine. Walk the beach.

Article: A "prime" number is a number that cannot be divided by any other number and stay whole (apart from itself and 1, of course). 2, 3, 5, 7, and 11 are examples of prime numbers.  Start with the numerator. From 24, branch off into 2 and 12. Since 2 is a prime number already, you're done with that branch! Then take 12 into two more numbers: 2 and 6. 2 is a prime number -- great! Now divide 6 into two numbers: 2 and 3. You now have 2, 2, 2, and 3 as your prime numbers. Move onto the denominator. From 60, branch off your tree to 2 and 30. 30 will then split into 2 and 15. Then split 15 into 3 and 5,both prime. You now have 2, 2, 3 and 5 as your prime numbers. Take the list of prime numbers you have for each number and write them out to be multiplied. You don't actually have to do the math -- this just makes it easier to see.  So, for 24, you have 2 x 2 x 2 x 3 = 24. For 60, you have 2 x 2 x 3 x 5 = 60 Any numbers that you see that are part of both numbers can be eliminated. In this case, what we have in common is a pair of twos and a 3. Goodbye!  What we are left with is 2 and 5 -- or 2/5! The same answer we got with the above method. if both numerator and denominator are even numbers, just think of splitting the number in half.  keep on doing it to both until they are to small to split any more.
Question: What is a summary of what this article is about?
Find the prime factors of the numerator and the denominator. Write the prime factorization of each number. Cancel out the common factors.