Boiler Blog | Nationwide Boiler Inc.

Nationwide Boiler news and events, industry updates, technical resources and more. You hear it first on The Nationwide Boiler Blog!

Non-Return Valves: What, Why and How

You may not know this, but all Nationwide Boiler rental boiler systems come standard with a non-return valve. These valves are vital to protect the boiler and other plant equipment and are required by the ASME. Let’s review the basics.

What is a non-return valve?
The main function of a non-return valve (NRV), otherwise known as stop or check valve, is to allow steam flow in one direction, and automatically prevent backflow. In other words, they prevent steam from flowing back to the main header of the boiler, or back to a boiler that has failed or is off-line.

An NRV can also be used to isolate a boiler during blowdown and shutdown, and to assist in returning a boiler to operation after any planned or unplanned maintenance.

Why are they needed?
The non-return valve is really just another safety device. Although the NRV should not be relied upon for primary shut-off, it does restrict the flow of steam back from the header into the boiler, which could be disastrous.

Per ASME standards, one NRV is required for one-boiler, high pressure applications (above 15 psig). For high-pressure applications involving multiple steam boilers with manholes that are connected to a common steam main, the steam connection from each boiler must be fitted with two stop valves. The first valve must be automatic and the second should be outside-screw-and-yoke (OS&Y).

How do they prevent backflow?
Non-return valves are flow sensitive, and rely on the steam flow to open and close. The internal disc opens and allows the flow of steam through the valve. The disc will begin to close as forward steam flow decreases or is reversed, depending on the design.

As you can see, non-return valves are critical for any steam boiler system, temporary or permanent. Be sure to check with your temporary equipment supplier to ensure that they include an NRV with their boiler rental package.
Continue reading
  18528 Hits
  3 Comments
Recent Comments
Guest — Tarun bag
Dismantleing process of the valve.
Friday, 11 January 2019 09:44
Guest — Tarun ag
Dismantleing process of the valve?
Friday, 11 January 2019 09:45
Guest — Joe Haber..
How often should a High Pressure NRV be rebuilt or replaced?
Thursday, 21 March 2019 12:12
18528 Hits
3 Comments

9/11 - To Honor and Remember

In remembrance of all whom we lost on September 11, 2001. We will never forget.
  2219 Hits
  0 Comment
2219 Hits
0 Comment

B&W MEGTEC Environmental Control Technologies

Nationwide Boiler is excited to announce that we will now be representing the Babcock & Wilcox (B&W) line of MEGTEC environmental equipment. This exclusive agreement covers the entire state of California and eastern Nevada. 

B&W MEGTEC is a leading global supplier of environmental control technologies. Their line of emission control equipment is used for the removal or recovery of VOC, SOx, NOx, particulate, and/or mercury from flue gas or existing processes. MEGTEC’s environmental solutions will pair well with Nationwide Boiler’s proven CataStak™ SCR system.

For more information, check out our latest press release!
  2776 Hits
  0 Comment
2776 Hits
0 Comment

"...Integrity, Dependability, Real Customer Service"

Integrity, Dependability, and Real Customer Service is more than just a tagline for the employees of Nationwide Boiler, it’s also what drives most every action and decision relating to the company’s customers, vendors, and stakeholders.

Integrity is more than doing what we say we will do; it’s striving for high levels of ethics and fairness, resulting in a relationship with others built on trust. Nationwide Boiler’s impressive repeat customer list illustrates five decades of superior integrity in providing solutions and products that meet the high demands of the industry. Our commitment to provide reliable rental boiler equipment performance, no matter what challenges may occur, while ensuring complete customer satisfaction, further solidifies our consistent efforts in doing the right thing in the most reliable way.

Dependability is why our customers call on Nationwide Boiler no matter what the boiler need. Our primary boiler maintenance and inspection programs result in equipment that is delivered ready to operate, helping to minimize lengthy downtime and achieve rapid installation and operation. In addition, high levels of satisfaction through the purchase of new and used equipment provide plant operations with years of reliable boiler performance from the most trusted boiler manufacturers in the world.

Real customer service is listening to our customers and building a partnership that lasts before, during, and after a job. We support and provide quality solutions that not only meet, but exceed the unique requirements of every application. Moreover, Nationwide Boiler’s technical experience and knowledgeable sales and service teams equip our customers with the information, tools and guidance needed to help make the most informed decisions and provide the most effective solution.

Does Nationwide Boiler deliver, acting on our tagline? We would like to know you thoughts. Please complete our one minute quality quiz to let us know.
  2347 Hits
  0 Comment
2347 Hits
0 Comment