Outside diameter (OD) is the outside diameter of the pipe and is fixed for a given size. The pipes are always specified by outside diameter, never by inside diameter.

We require that the product has not been used and is in resalable condition. Some products on our website are marked as “Non-Returnable”. These products will not be accepted as a return and no refund will be issued. If you are unsure of whether your product can be returned, please contact our customer service team and they will assist you.

The name NPS is based on the earlier Iron Pipe Size (IPS) system. That IPS system was established to designate the pipe size. The size represented the approximate inside diameter of the pipe in inches. An IPS 6" pipe is one whose inside diameter is approximately 6 inches. Users started to call the pipe as 2inch, 4inch, 6inch pipe and so on. To begin, each pipe size was produced to have one thickness, which later was termed as standard (STD) or standard weight (STD.WT.). The outside diameter of the pipe was standardized.

Nominal pipe size NPS is a dimensionless designator of pipe size. It indicates standard pipe size when followed by the specific size designation number without an inch symbol. For example, NPS 6 indicates a pipe whose outside diameter is 168.3 mm. The NPS is very loosely related to the inside diameter in inches, and NPS 12 and smaller pipe has outside diameter greater than the size designator. For NPS 14 and larger, the NPS is equal to 14inch. For a given NPS, the outside diameter stays constant and the wall thickness increases with larger schedule number. The inside diameter will depend upon the pipe wall thickness specified by the schedule number.

The pipe schedule sets the pipe Wall Thickness (WT). Obviously increasing the wall thickness of the pipe increases the mechanical strength of the pipe, allowing it to handle higher design press. As the schedule is increased, so does the wall thickness.

Nominal Pipe Size (NPS) is a North American set of standard sizes for pipes and fittings used for high or low pressures and temperatures. Pipe size is specified with two non-dimensional numbers: a nominal pipe size (NPS) for diameter based on inches, and a schedule (Sched. or Sch.) for wall thickness.

Burundi, Comoros, Djibouti, Eritrea, Ethiopia, Kenya, Madagascar, Malawi, Mauritius, Mayotte, Mozambique, Reunion, Rwanda, Seychelles, Somalia, Tanzania, United Republic of Uganda, Zambia, Zimbabwe, Angola, Cameroon, Central African Republic, Chad, Congo (Brazzaville), Congo, Democratic Republic of the Equatorial Guinea, Gabon, Sao Tome and Principe, Algeria, Egypt, Libyan Arab Jamahiriya, Morroco, South Sudan, Sudan, Tunisia, Western Sahara, Botswana, Lesotho, Namibia, South Africa, Swaziland, Benin, Burkina Faso, Cape Verde, Cote d’Ivoire (Ivory Coast), Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Mauritania, Niger, Nigeria, Saint Helena, Senegal, Sierra Leone, Togo

In the event that you require a refund or need to return your product, please contact Pharmacy2Home within 30 days of your purchase, by calling us at 1-800-884-5723 and we will make arrangements to issue the proper refund and take back the product.

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.

Bahrain, Iraq, Iran, Israel, Jordan, Kuwait, Lebanon, Oman, Palestine, Qatar, Saudi Arabia, Syria, United Arab Emirates, Yemen

Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, United Kingdom

Albania, Andorra, Belarus, Bosnia, Croatia, European Union, Faroe Islands, Gibraltar, Guerney and Alderney, Iceland, Jersey, Kosovo, Liechtenstein, Macedonia, Man, Island of Moldova, Monaco, Montenegro, Norway, Russia, San Marino, Serbia, Svalbard and Jan Mayen Islands, Switzerland, Turkey, Ukraine, Vatican City State (Holy See)

Anguilla, Antigua and Barbuda, Aruba, Bahamas, Barbados, Bonaire, Saint Eustatius and Saba, British Virgin Islands, Cayman Islands, Cuba, Curaçao, Dominica, Dominican Republic, Grenada, Guadeloupe, Haiti, Jamaica, Martinique, Monserrat, Puerto Rico, Saint-Barthélemy, St. Kitts and Nevis, Saint Lucia, Saint Martin, Saint Vincent and the Grenadines, Sint Maarten, Trinidad and Tobago, Turks and Caicos Islands, Virgin Islands (US), Belize, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Falkland Islands (Malvinas), French Guiana, Guyana, Paraguay, Peru, Suriname, Uruguay, Venezuela, Bermuda, Canada, Greenland, Saint Pierre and Miquelon

As the industrial requirements handling higher pressure fluids, pipes were manufactured with thicker walls, which has become known as an extra strong (XS) or extra heavy (XH). The higher pressure requirements increased further, with thicker wall pipes. Accordingly, pipes were made with double extra strong (XXS) or double extra heavy (XXH) walls, while the standardized outside diameters are unchanged. Note that on this website only terms XS and XXS are used.

Afghanistan, Armenia, Azerbaijan, Bangladesh, Bhutan, Brunei Darussalam, Cambodia, China, Georgia, Hong Kong, India, Indonesia, Japan, Kazakhstan, South Korea, Kyrgyzstan, Laos, Macao, Malaysia, Maldives, Mongolia, Myanmar (ex-Burma), Nepal, Phillipines, Singapore, Sri Lanka (ex-Ceilan), Taiwan, Tajikistan, Thailand, Timor Leste (West), Turkmenistan, Uzbekistan, Vietnam

Nominal Bore (NB) is the European designation equivalent to NPS is DN (diamètre nominal/nominal diameter/Durchmesser nach Norm), in which sizes are measured in millimeters. NB is also frequently used interchangeably with NPS.