04232018Mon
Last updateFri, 20 Apr 2018 5pm

i

Air Valves in Piping Systems

Air Valves in Piping Systems

Liquid piping systems are prone to colle...

Are Valves from Low-Cost Countries Getting Better?

Are Valves from Low-Cost Countries Getting Better?

The last 25 years have seen standards cr...

Managing the Generation Gap: Much Ado About Nothing?

Managing the Generation Gap: Much Ado About Nothing?

The baby boomer generation was the most ...

SubscribeSPR18

FREE SUBSCRIPTION*

• Print magazine
Digital magazine
• VALVE eNews
Read the latest issue

*to qualified valve professionals in the U.S./Canada

The Weekly Report

New Products

  • ja-news-2
  • ja-news-3

Industry Headlines

Weir Group Plans to Sell Flow Control Division

Friday, 20 April 2018  |  Chris Guy

The Weir Group’s board of directors will initiate a process to sell the Flow Control division. This process will focus on maximizing value for sha...

Readmore

Loading...
Advertisement
i

Industry Headlines

Weir Group Plans to Sell Flow Control Division

2 DAYS AGO

The Weir Group’s board of directors will initiate a process to sell the Flow Control division. This process will focus on maximizing value for shareholders, with all options to be considered and no fixed timetable. Proceeds will be used to further reduce leverage and to fund future investment in...

Readmore

Emerson and BlueFin Form Strategic Partnership

3 DAYS AGO

Emerson and BlueFin have signed a working partnership agreement to deliver the Roxar gauge technology to the U.S. Gulf of Mexico (GoM) region. The partnership will deliver a combined offering of Emerson's technology coupled with BlueFin's installation services and chemical injection systems.

BlueFin, a...

Readmore

OECD Natural Gas Production Up 2.4% in 2017

3 DAYS AGO

An assessment of monthly data shows that in 2017 Organization for Economic Co-operation and Development (OECD) natural gas production grew by 2.4% compared to 2016. This growth was driven by increases in production across all OECD regions, particularly in Asia Oceania (+17.7%), whilst the Americas and...

Readmore

Major Trends Changing the Chemical Industry

5 DAYS AGO

“The accelerated globalization of the chemicals market is one of four major trends that we at SAP see shaping the chemical industry through the remainder of 2018 and beyond,” writes Stefan Guertzgen, global senior director for industry solution marketing, chemicals at SAP.

“Amid such ...

Readmore

Beige Book: Solid Outlook Despite Tariff Concerns

3 DAYS AGO

Economic activity continued to expand at a modest to moderate pace across the 12 Federal Reserve Districts in March and early April. Outlooks remained positive, but contacts in various sectors including manufacturing, agriculture and transportation expressed concern about the newly imposed and/or prop...

Readmore

IMF Predicting Global Economic Upswing

4 DAYS AGO

World growth strengthened in 2017 to 3.8%, with a notable rebound in global trade. It was driven by an investment recovery in advanced economies, continued strong growth in emerging Asia, a notable upswing in emerging Europe, and signs of recovery in several commodity exporters. Global growth is exp...

Readmore

Advertisement

The Well-Functioning Steam Trap

vmwnt09 beyond valves 1Ultrasonic instruments are used to test a thermodynamic steam trapSteam traps are the most important link between the steam and condensate system. Malfunctioning steam traps can waste tremendous amounts of money. Here is an example: A single inverted bucket steam trap (with a one-eighth-inch orifice) blowing-thru in a 150 psi, where the steam cost is $11.00 per 1,000 lbs. of steam produced, will waste 62.49 lbs. of steam per hour and cost approximately $6,022 in fuel losses per year.

 

Steam Traps Defined

For those who are not familiar with the steam trap, it is an automatic valve that, when operating properly, opens to purge a steam system of condensate and closes with the presence of steam.

There are three types of steam traps:

  • Density operated, which includes the inverted-bucket (IB) and the float and thermostatic (FT) types
  • Thermostatic (TH), specifically, the balance-pressure thermostatic (BPT) type
  • Thermodynamic (TD), either the disc or impulse type

Trap Characteristics

vmwnt09 beyond valves 2An inverted bucket steam trapFloat and thermostatic traps consist of a ball float and a thermostatic bellows element. As condensate flows through the body, the float rises or falls, opening the valve according to the flow rate. The thermostatic element discharges air from the steam lines. They are good in heavy and light loads and on high and low pressure, but are not recommended where water-hammer is a possibility.

When these traps fail, they usually fail closed. However, the ball float may become damaged and sink down, failing in the open position. The thermostatic element may also fail and cause a fail-open condition.

Thermostatic traps have, as the main operating element, a metallic corrugated bellows that is filled with an alcohol mixture that has a boiling point lower than that of water. The bellows will contract when in contact with condensate and expand when steam is present. Should a heavy condensate load occur, such as in start-up, the bellows will remain in a contracted state, allowing condensate to flow continuously. As steam builds up, the bellows will close. Therefore, there will be moments when this trap will act as a “continuous flow” type while at other times it will act intermittently as it opens and closes to condensate and steam, or it may remain totally closed.

These traps adjust automatically to variations of steam pressure but may be damaged in the presence of water-hammer. They can fail open should the bellows become damaged or due to particulates in the valve hole that will prevent adequate closing. Sometimes the trap becomes plugged and will fail closed.

Inverted bucket traps have a “bucket” that rises or falls as steam and/or condensate enters the trap body. When steam is in the body, the bucket rises, closing a valve. As condensate enters, the bucket sinks down, opening a valve and allowing the condensate to drain.

Inverted bucket traps are ideally suited for water-hammer conditions but may be subject to freezing in low temperature climates if not insulated. When an inverted bucket trap fails, it fails open due to the bucket losing its prime and sinking, or from impurities in the system that may prevent the valve from closing.

  • Latest Post

  • Popular

  • Links

  • Events

BUYERS GUIDE 300x220

Looking for a career in the Valve Industry?

ValveCareers Horiz

To learn more, watch the videos below or visit ValveCareers.com a special initiative of the Valve Manufacturers Association