On the Internet you can also find pages with the ranking of plumbers, where are published opinions on them.
Therefore, the more plumbers are trying to do their job well, because they know that some negative reviews posted about them can effectively discourage the use of their services.
The difference between pipes and tubes is simply in the way it is sized.
PVC pipe for plumbing applications and galvanized steel pipe for instance, are measured in IPS (iron pipe size).Copper tube, CPVC, PeX and other tubing is measured nominally, which is basically an average diameter. These sizing schemes allow for universal adaptation of transitional fittings. For instance, 1/2" PeX tubing is the same size as 1/2" copper tubing.
1/2" PVC on the other hand is not the same size as 1/2" tubing, and therefore requires either a threaded male or female adapter to connect them.
When used in agricultural irrigation, the singular form "pipe" is often used as a plural.7 Pipe is available in rigid "joints", which come in various lengths depending on the material.Tubing, in particular copper, comes in rigid hard tempered "joints" or soft tempered (annealed) rolls.
PeX and CPVC tubing also comes in rigid "joints" or flexible rolls.The temper of the copper, that is whether it is a rigid "joint" or flexible roll, does not affect the sizing.7 The thicknesses of the water pipe and tube walls can vary. Pipe wall thickness is denoted by various schedules or for large bore polyethylene pipe in the UK by the Standard Dimension Ratio (SDR), defined as the ratio of the pipe diameter to its wall thickness.
Pipe wall thickness increases with schedule, and is available in schedules 20, 40, 80, and higher in special cases.
The schedule is largely determined by the operating pressure of the system, with higher pressures commanding greater thickness.Copper tubing is available in four wall thicknesses: type DWV (thinnest wall; only allowed as drain pipe per UPC), type 'M' (thin; typically only allowed as drain pipe by IPC code), type 'L' (thicker, standard duty for water lines and water service), and type 'K' (thickest, typically used underground between the main and the meter).Because piping and tubing are commodities, having a greater wall thickness implies higher initial cost.Thicker walled pipe generally implies greater durability and higher pressure tolerances. Wall thickness does not affect pipe or tubing size.8 1/2" L copper has the same outer diameter as 1/2" K or M copper.
The same applies to pipe schedules.
As a result, a slight increase in pressure losses is realized due to a decrease in flowpath as wall thickness is increased.
In other words, 1 foot of 1/2" L copper has slightly less volume than 1 foot of 1/2 M copper.citation needed Demand for copper products has fallen due to the dramatic increase in the price of copper, resulting in increased demand for alternative products including PEX and stainless steel. Źródło: https://en.wikipedia.org/wiki/Water_pipe#Difference_between_pipes_and_tubes
Much of the plumbing work in populated areas is regulated by government or quasi-government agencies due to the direct impact on the public's health, safety, and welfare..Plumbing installation and repair work on residences and other buildings generally must be done according to plumbing and building codes to protect the inhabitants of the buildings and to ensure safe, quality construction to future buyers.If permits are required for work, plumbing contractors typically secure them from the authorities on behalf of home or building owners.citation needed In the United Kingdom the professional body is the Chartered Institute of Plumbing and Heating Engineering (educational charity status) and it is true that the trade still remains virtually ungoverned; there are no systems in place to monitor or control the activities of unqualified plumbers or those home owners who choose to undertake installation and maintenance works themselves, despite the health and safety issues which arise from such works when they are undertaken incorrectly; see Health Aspects of Plumbing (HAP) published jointly by the World Health Organization (WHO) and the World Plumbing Council (WPC). WPC has subsequently appointed a representative to the World Health Organization to take forward various projects related to Health Aspects of Plumbing. In the United States, plumbing codes and licensing are generally controlled by state and local governments. At the national level, the Environmental Protection Agency has set guidelines about what constitutes lead-free plumbing fittings and pipes, in order to comply with the Safe Drinking Water Act.Źródło: https://en.wikipedia.org/wiki/Plumbing#Regulation