# Piping

## Hazen-Williams vs Darcy-Weisbach

Both Hazen-Williams and Darcy-Weisbach equations compute head loss due to friction in a pipe. Hazen-Williams coefficient is a function of only the pipe roughness vs Darcy-Weisbach which considers internal roughness,…

## 3″ Sewer Pipe – Slope, Dimensions, and Relining

A 3-inch sewer pipe slope should be between 3/16″ and 5/16″ per foot. In this article, we will review how to determine the slope of a 3″ sewer pipe, a…

## SDR 11 vs. SDR 17

The SDR rating scheme for the pipe includes SDR 11 and SDR 17. At a 100°F operating temperature, SDR 11 provides a pressure rating of 126psi vs SDR 17, which…

## SDR 21 vs SDR-26

SDR 21 and SDR 26 are both under the SDR rating system for the pipe. SDR 21 has a 200 psi rating, vs SDR 26 which has a 160 psi…

## Pipe Obvert Elevation – Implication, Calculation, and Applications

Pipe obvert elevation is the vertical distance between the inside-top of a pipe and any datum. Moreover, the term ‘obvert’ means to turn. The obvert measurement mirrors the pipe invert,…

## SDR 11 vs. SDR 13.5 – Comparision and Pipe Properties

SDR 11 vs. SDR 13.5 both categorize under the SDR rating system for the pipe. The SDR (standard dimension ratio) is a pressure pipe rating method. The SDR increases as…

## NPT vs NPTF, NPS, JIC, MIP – A Comparison of Various Threads

NPT and NPTF are standard thread designs that enjoy wide levels of adoption in industry. For pipes, the NPT threading requirements should be as per ANSI B1.20.1, while NPTF requirements…

## SDR 26 vs SDR 35 – Comparison and Pipe Properties

SDR 26 and SDR 35 both categorize under the SDR rating system for pipe. At 5% deflection, the SDR 26 pipe can undergo pressurization of 115psi vs the SDR 35…

## Spectacle Blind

A spectacle blind is a key component of pipeline systems that provides isolation of certain sections as the need arises. Typically, the entire device consists of a blind and a…

## Stub-in Pipe – How it Works, vs. Stub On, and Stub Tube

Stub-in pipe refers to a branch connection between a pipe and a header. Making this connection involves drilling a hole into the header of the run pipe and fitting the…