Bitumen Sampling Valve

Many state DOTs now require closer monitoring of asphalt cements, especially when they include polymers. Thus, samples are taken more frequently from the asphalt storage tanks than in the past.

As a result, hot mix producers are paying more attention to the sampling provisions on their asphalt storage tanks. Many contractors are now ordering their new storage tanks with a special sampling valve. Sampling valves can also be retrofitted into old storage tanks.

However, the tank must be drained before the installation is made. Sampling valves have important advantages over other types of valves and are well worth their extra cost. They are designed specifically for sampling. Consequently, they virtually eliminate the hazards and difficulties associated with using other types of valves for that purpose.
Sampling valves are usually manually operated and feature a screw stem operated by a hand crank. They are virtually clog-free because of the way the valve is designed and mounted in the tank. (They do not need a hot oil jacket.) Moreover, they are leak-free when closed and provide free-flow when opened.

In a horizontal asphalt tank the valve is usually installed in one end, about 24 inches above the bottom. In a vertical asphalt tank it is installed in the side, about the same height above the bottom.

Roadtec Comfort Drive

The Roadtec Comfort Drive TM operator system is designed for maximum comfort and ease of operation. There are two complete operators stations, each with individual consoles, allowing the paverto be oper- ated from either side. A main center console houses gauges, circuit breakers and wiring distribution. The propel console and function console are mounted to either side of the operators seat. These consoles are easily interchangeable from side to side to accommodate left or right-handed operators. This positioning literally places the controls at your fingertips and allows greater visibility over the entire operation. Controls for the track mounted machines are identical with dual joysticks and the steering wheel removed.

Electrically Heated Asphalt Screed

The single biggest advantage to electric screed heat is that the screed plate(s) are heated evenly from front to backand from end to end through a patent pending process. Stainless steel heat elements are attached to aluminum heat distribution plates, which contact the screed plate(s). This makes for a very positive transfer of heat from the ements directly to the screed plate(s) and eliminates the traditional "hot" spots found with diesel or propane burners that typically place a great deal of heat directly under the burner but less heat farther away. This positive connection insures that the heat stays on the screed plates where it's needed and away from the screed frame where it's not needed. This will lead to increased screed life due to the elimination of warpage of the screed plates and less heat stress on the screed framework. In addition, all diesel fumes and residue associated withtraditional oil fueled burners are eliminated completely, making for a cleaner and safer environment for the paving crew.

Roadtec is the first U.S. paver manufacturer to make fully electric screed heat standard equipment on every model paver screed, effective January 2000.

All Roadtec electrically heated screeds include the following features:
- 3 phase 34 kilowatt (continuous) hydraulically driven generator.
- 30 kilowatts of power for screed heat and another 4 kilowatts available for 120 VAC night lighting.
- Sufficient power to heat up to 24' of screed while operating night lights (enough power to heat 27'of screed if no night lights are in use).
- "Off-the-shelf" heating elements are replaceable stainless steel strip heaters that operate at 208 VAC, upto 1500watts per element.
- Full screed heat can be attained at 1400 engine RPM.
- Heat is thermostatically controlled through a thermocouple that senses actual screed plate temperatureand through a temperature controller that is factory preset to 250 degrees F (set point can be
changed). A heat controller compares actual screed plate temperature with set point and turns elements oo/off to maintain desired temperature. Digital display shows set point and actual screed plate temperatures.
- Uniform screed heating from ambient temperature to 250 degrees F in approximately 30 minutes.
- Easy plug-in connect points for add-on screed extensions.
- Prewired 120 VAC outlets for night paving lights or other 120 V uses.
- All enclosures are NEMA approved

Send mail to georgec@qpave.com.au with questions or comments about this web site.
All sales enquires to paul.c@qpave.com.au                                                                                                                     Last modified: July 29, 2001