http://www.engineeringnews.co.za
  SEARCH
Login
R/€ = 16.93Change: -0.10
R/$ = 14.74Change: -0.13
Au 1276.02 $/ozChange: -11.23
Pt 1053.50 $/ozChange: -14.00
 
 
Note: Search is limited to the most recent 250 articles. Set date range to access earlier articles.
Where? With... When?








Start
 
End
 
 
And must exclude these words...
Close Main Search
Close Main Login
My Profile News Alerts Newsletters Logout Close Main Profile
 
Agriculture   Automotive   Chemicals   Competition Policy   Construction   Defence   Economy   Electricity   Energy   Environment   ICT   Metals   Mining   Science and Technology   Services   Trade   Transport & Logistics   Water  
What's On Press Office Tenders Suppliers Directory Research Jobs Announcements Letters About Us
 
 
 
RSS Feed
Article   Comments   Other News   Research   Magazine  
 
 
Nov 04, 2011

Stringent legislation drives demand for VCP pressure release valves

Back
Agriculture|Construction|Africa|Cement|Environment|Health|Pipe|Safety|Welding|Africa|Equipment|Product|Steel|Environmental|Pipe|Valves
Agriculture|Construction|Africa|Cement|Environment|Health|Pipe|Safety|Welding|Africa|Equipment|Steel|Environmental|Pipe|Valves
agriculture|construction|africa-company|cement|environment|health|pipe-company|safety|welding|africa|equipment|product|steel|environmental|pipe|valves



Multidisciplinary equipment supplier WAM South Africa says more stringent safety and environmental laws have led to companies conforming to the use of its over/under (VCP) pressure relief valve.
These new laws include the South African government’s imposition of European standards on the South African pressure equipment sector in October last year.

Further, the new pressure equipment regulations (PERs), promulgated under the Occupational Health and Safety Act, of 1993, previously referred to as the vessels-under-pressure regulations, came into effect in October 2009.

Competent persons qualified under the South African Institute of Welding and approved by the South African Qualification and Certification Commit- tee to pressure-test pressure vessels had until April 1 to conform with the new PERs.

“Since the laws on pressure silos have become a matter of safety for personnel and the environment, customers have been resorting to our VCP pressure relief valves,” WAM South Africa GM Emilie Marchand says.

Pressure Vessels

She explains that a silo becomes a pressure vessel when it is filled and subjected to overpressure. In such cases, the VCP valve will open and release excess pressure exceeding 1 bar to prevent the silo from exploding or being damaged.

However, when the silo is being discharged, underpressure can also occur. “In this case, the valve will open up and allow pressure from the environment to enter the silo to regulate the pressure,” Marchand adds.

The VCP valve consists of a cylindrical casing with a bottom flange that is connected to a spigot on the silo’s roof. A disc-shaped inner steel lid for nega- tive pressure operation is held in position by a central spring rod, while an outside steel ring for excess pressure is kept in position by three spring rods, gaskets and a weather-protection cover.

Marchand says helical springs keep the valve lids closed when the pressure value remains within the preset limits. The three spring rods on the outside of the valve keep the external ring-shaped lid firmly closed as long as the force generated by the pressure inside the silo does not exceed the spring force.

“Once the pressure exceeds the preset value, the lid is pushed up and the pressure can escape. The smaller lid covers the central circular opening of the external lid from below. It is held in the middle by a single spring rod and is pressed onto the external lid by the normal air pressure inside the silo,” she adds.

In the event of suction pressure, the spring is compressed and enables the lid to drop. The air entering the silo from outside ensures rapid pressure balance and pushes the central lid back up into the closed position.

However, Marchand says, spillage on construction and cement plants is problematic, owing to the lack of a regulating body to monitor the pressure with which tankers offload their product pneumatically into silos.

“Tankers often increase their off- load pressure to help [speed up] the process. “This results in major overpressurisation in the silos, which causes the VCP valves to constantly open and spillage to occur. “This is worrying, as these valves are only supposed to open in the event of an emergency,” she points out.

Regulation

It is difficult for plant managers to regu- late the tankers, which are owned and managed by third-party companies.

To deal with this challenge, WAM South Africa has offered its VHS membrane pressure relief valve as a solution.

The VHS is based on the same con- cept as the VCP valve; however, it has an outlet that enables it to be connected to a pipe. “If the valve does open, owing to overpressure, the spillage can be channelled back into the silo. This has various environmental benefits, especially with the spillage of fly ash or cement,” Marchand says.

WAM South Africa’s primary focus has historically been on batching plants; however, she states that the company is turning its attention to other sectors, including the agriculture, food and beverage and glass sectors.

Edited by: Chanel de Bruyn
Creamer Media Senior Deputy Editor Online

To subscribe email subscriptions@creamermedia.co.za or click here
To advertise email advertising@creamermedia.co.za or click here
 
Comment Guidelines (150 word limit)
 
 
 
 
 
 
 
 
Other Valves News
SMOOTH DESIGN The absence of cavities in the design of the plug valve ensures a smooth slurry flow
Valve manufacturer AZ-Armaturen (AZ) South Africa delivered a total of 22 high-pressure plug valves to a mineral sands operation near Richards Bay, KwaZulu-Natal over two occasions, once in June and once in July, says AZ GM Erich Ermel, adding that the valves ranged...
MARK WILSON Vamcosa has hosted a series of open sessions to inform industry stakeholders about designation
Since the Department of Trade and Industry (DTI) designated valves as a priority product that needed to be locally manufactured, in March last year, it has become quite a challenge for the valves industry to implement the DTI’s vision, says Valve and Actuator...
PASEKA LESOLANG A single leaking toilet can cause a loss of between 30 ℓ and 700 ℓ of water daily
Water-savings solutions company Water Hygiene Convenience (WHC) CEO Paseka Lesolang won first prize at the City of Johannesburg’s Green City Startup Awards, in September, comprising R1-million for his innovation, the Leak-Less Valve.
More
 
 
Latest News
Updated 46 minutes ago SABMiller and Coca-Cola have agreed concessions with the South African government to win approval for a deal to combine their soft-drink operations, the companies said on Wednesday. The concessions, agreed with the South African Ministry of Economic Development,...
Updated 52 minutes ago National Treasury was close to naming a new board for the struggling national carrier South African Airways, Deputy Finance Minister Mcebisi Jonas said on Wednesday. “We are finalising the process of appointing a full-strength board,” Jonas said in the debate on the...
Updated 57 minutes ago South Africa's Finance Minister Pravin Gordhan said on Wednesday he favoured a minority equity partner buying into struggling national airline South African Airways (SAA) at "some stage". SAA, which has been placed under National Treasury oversight, has already had...
More
 
 
Recent Research Reports
Automotive 2016: A review of South Africa's automotive sector (PDF Report)
Creamer Media’s Automotive 2016 Report provides an overview of South Africa’s automotive industry over the past 12 months. The report provides insight into local demand and production, vehicle imports and exports, investment and competitiveness in the sector, as well...
Energy Roundup – April 2016 (PDF Report)
The April 2016 roundup covers activities across South Africa for March 2016 and includes details of a North Gauteng High Court Judge’s dismissal of a court application to postpone the 9.4% electricity tariff increase, which the National Energy Regulator of South...
Electricity 2016: A review of South Africa's electricity sector (PDF Report)
Creamer Media’s Electricity 2016 report provides an overview of South Africa’s electricity sector, focusing on State-owned power utility Eskom and independent power producers, electricity planning, transmission, distribution and the theft thereof, besides other issues.
Energy Roundup – March 2016 (PDF Report)
The March 2016 roundup covers activities across South Africa for February 2016 and includes details of the Department of Energy’s plans to announce the preferred bidders for the first tranche of the coal independent power producer procurement programme; the Council...
Steel 2016: A review of South Africa's steel sector (PDF Report)
Creamer Media’s Steel 2016 Report examines South Africa’s steel industry over the past 12 months. The report provides insight into the global steel market and and particularly into South South Africa’s steel sector, including production and consumption, main...
Construction 2016: A review of South Africa's construction industry (PDF Report)
Creamer Media’s Construction 2016 Report examines South Africa’s construction industry over the past 12 months. The report provides insight into the business environment; key participants; local demand; geographic diversification; corporate activity; black economic...
 
 
 
 
 
This Week's Magazine
The two spent-fuel pools at Eskom’s 1 800 MW Koeberg nuclear power station, in the Western Cape, will be full by 2018, increasing the urgency on the State-owned utility to begin pursuing alternative storage options. Koeberg has, over the past 32 years, accumulated a...
South Africa lacks the skills necessary to implement the government’s plan to build 9.6 GWe of new nuclear energy capacity, warns nuclear-qualified Quality Strategies International CEO David Crawford. “Apart from the concern about the affordability of the programme,...
DOROS HADJIZENONOS The 700-series devices provide network security monitoring, app control, URL filtering, VPN security, antivirus, antispam, antibot, and advanced intrusion prevention and detection functionality
Cybersecurity multinational Check Point has released its latest 700-series cybersecurity systems for small businesses, which draw on its international threat intelligence to provide up-to-date cybersecurity, says Check Point South Africa country manager Doros...
Daimler Trucks and Buses Southern Africa (DTBSA) saw a marked slip in new-vehicle sales in 2015 compared with 2014, with sales dropping from 5 897 units to 5 300 units. The decline came as the South African new truck and bus market declined from 31 558 units in 2014...
Group of 20 (G-20) economies threatened to penalise havens that don’t share information on their banking clients after the leak of the Panama Papers provoked a global uproar over tax evasion. The G-20 will consider “defensive measures” against financial centers and...
 
 
 
 
 
 
 
 
 
Alert Close
Embed Code Close
content
Research Reports Close
Research Reports are a product of the
Research Channel Africa. Reports can be bought individually or you can gain full access to all reports as part of a Research Channel Africa subscription.
Find Out More Buy Report
 
 
Close
Engineering News
Completely Re-Engineered
Experience it now. Click here
*website to launch in a few weeks
Subscribe Now for $149 Close
Subscribe Now for $149