There are many manufacturers of PPR pipe fittings and pipes. The raw material of PPR pipe fittings and pipes is polypropylene (random copolymer polypropylene). PPR pipe fittings and pipes are produced from different brands of raw materials. There are certain differences in performance, plus the level of production line. Different, the quality of PPR pipe fittings produced by various manufacturers has a large gap between good and bad. When using PPR pipe fittings, it must be inspected before installation, and the PPR pipe fittings can only be used after the quality is confirmed to be qualified. The selected ppr pipe fittings and pipes should first have the quality inspection report of the quality inspection department, and the ppr pipe fittings used for drinking water should also have the sanitary performance inspection report of the sanitary inspection department, and then the appearance quality of the pipes and fittings and the pipe should be inspected. Diameter and wall thickness, when inspecting ppr pipe fittings and pipes, the following items are mainly inspected according to national standards:
1. The appearance of ppr pipe fittings.
The color of ppr pipe fittings and pipes should be basically the same. The inner and outer surfaces of ppr pipe fittings and pipes should be smooth and flat without dents, bubbles and other surface defects that affect performance. PPR pipe fittings and pipes should not contain visible impurities; the surface of ppr pipe fittings should be smooth, flat, and not Defects such as cracks, bubbles, peeling and obvious impurities, severe shrinkage, uneven color, decomposition and discoloration are allowed.
2. The opacity of ppr pipe fittings.
Ppr pipe fittings and pipes should be opaque.
3. Pipe diameter and wall thickness of ppr pipe fittings.
According to GB/T18742.2-2002 national standard, ppr pipe fittings are divided into five series according to size: S5, S4, S3.2, S2.5, and S2. There is a corresponding relationship between ppr pipe fittings and pipe series S and nominal pressure. The specifications of ppr pipe fittings are represented by pipe series S and nominal outer diameter dn* nominal wall thickness en. Ppr pipe fittings mainly inspect the nominal outer diameter, average outer diameter and The corresponding wall thickness of the pipe series, the socket size of the pipe fitting and the corresponding nominal outer diameter.
4. Physical and mechanical properties and chemical properties of ppr pipe fittings.
Whether the hydrostatic test of ppr pipe fittings, the mass flow rate of melt, the thermal stability test under hydrostatic state, the longitudinal shrinkage rate of the pipe, and the impact test of simple beams meet the national standards, the inspection of materials for ppr pipe fittings can be checked. The content of the report and the retest report.
5. Whether the sanitary performance of ppr pipe fittings meets the national standards.
Ppr pipe fittings and pipes This item can be used to check the sanitary performance inspection reports of ppr pipe fittings and pipes by the health inspection department.
6. Applicability of ppr pipe fittings and pipe systems.
After the ppr pipe is connected to the pipe, it should pass the combined test of 8760 hours of internal pressure and 5000 thermal cycles.
The modern hinged bi-folding shower room is an independent and comfortable bathing environment as well as a completely exclusive bathing space. After you purchase a modern hinged bi-folding shower room that you love, how to fix the frame during installation? The following shower room manufacturers come to analyze it for everyone.
The installation of a modern hinged bi-folding shower room is first to find a place, punch holes, and then fix the frame. More tools are needed for position finding and punching, and the operation is more complicated.
One: Determine the drilling position, use tape measure + pen
The shower room must be fixed. The fixing method is generally to use screws to leave the holes on the aluminum alloy frame on the wall. All that needs to be done is to mark the corresponding position on the wall. The method is to put the frame on the wall, make sure the position is correct with a tape measure, and then mark the wall with a pencil.
2: Punch holes, use percussion drills
After setting the position, the next step is to punch. Punching is also divided into two steps. First, use a circular percussion drill to make a shallower hole at the marked location on the wall; construction tips: the bathroom wall has been covered with bricks, which is relatively hard. In order to make drilling easier, you can wet the drill bit. In addition, you can pour some water while drilling; after drilling the prototype mark hole, the next step is to use a spiral with stronger impact. The drill is out. On the basis of the shallower holes that have been punched, make a deeper hole.
Three: Install rubber pellets, use a hand hammer
Before screwing the screws into the wall, you need to install the expansion rubber particles in the holes first. The rubber particles can better tighten the screws. Use a hand hammer to knock the rubber particles into the drilled hole.
4: Fix the frame, use an electric screwdriver
After the above steps are completed, you can install the shower room frame, put the bottom frame on the water retaining strip, and then fix the frame. The method is to use an electric screwdriver to drive the screws into the wall to fix the frame.
In order to catch up with the fashion trend, most people who play basketball now like to wear two silicone bracelets on their wrists, but they don't understand the use of silicone bracelets. The following is a brief introduction to the use of silicone bracelets.
1. In order to facilitate team identification.
When playing basketball, as an unknown player, in order to have some perfect cooperation in the game, such as air relay, etc., they often have to reach out to ask for the ball, and their sign of judging their teammates is the silicone bracelet on their wrists. s color. In the United States, streetball masters often have 4-5 different colored silicone bracelets in their pockets to facilitate team formation.
2. Prevent sweat from flowing on the player's hands and cause the phenomenon of slipping the ball.
Since the silicone bracelet is made of environmentally friendly silicone, it can effectively absorb the sweat discharged from the human body and prevent the sweat from flowing to the player's hands, thereby avoiding the phenomenon of slipping the ball.
3. Fashionable and trendy decorations.
The color of the silicone bracelet is colorful, and you can choose the color and style you like according to your own preferences. After wearing it, matching with your own clothes can play a very good role in decoration and embellishment. It is a must-have for trendy people who catch up with fashion.
4. In order to convey the belief of the wearer.
In today's society, people have more speech rights, and there are many ways to express their thoughts and beliefs. Because the DIY of the silicone bracelet is very flexible, it can completely engrave the LOGO text you want to express on the wrist band according to people's requirements, so as to achieve the role of the wrist band to convey beliefs.
More and more people turn to online shopping this year because of the COVID-19, from small-size items, such as daily grocery, sports tools, to big-size items, such as light products or even furniture. When it comes to light products, most people tend to know whether it’s safety compliant, UL, ETL, or CSA listed, but always ignore FCC certification. So, can I buy a light product without FCC certification from an online store? The answer is yes, and no.
Then, what’s FCC certification? You may already know that FCC is Federal Communications Commission. The FCC office of engineering and technology laboratory division has rules for lighting products to ensure these devices do not cause harmful interference to radio communications services. It’s mandatory for most lighting products. Most lighting products generate not only light but also radiofrequency. For example, LED lights need to transfer high-voltage sinewave alternative current to low-voltage stable direct current to turn on the transistors in LED chips. This electric transformation and distortion will inevitably generate radiofrequency.
Suppose it’s a traditional light fixture, such as an 18-light chandelier with medium screw bases. In that case, FCC certification is not required because the voltage on each lamp socket is the same as line voltage, with no transformation or distortion. But for the bulbs mounted on the traditional light fixture, FCC certification is mandatory, no matter they are incandescent, halogen, CFL, or LED.
LED light must be FCC listed if it is connected directly to line voltage. Some LED lights to adopt FCC certified LED driver, which is good, but not enough if the LED driver is not a detachable part, the whole LED light must be listed as a whole. Take the LED vanity light as an example, the LED driver is mounted inside the backplate with 3M glue and not allowed to unmount by the customer, and then the LED vanity light must be FCC certified.
The LED light doesn't need FCC certification if connected to a low-voltage direct current power source, such as a 12V or 24V LED driver. Take the LED strip light as an example. Its electronic components are pure direct current within the LED strip lights; there is voltage dropdown from the LED driver's outlet, but no transformation or distortion. For sure, the 12V or 24V LED driver must be FCC listed.
For lighting products, UL, ETL, or CSA certification is not mandatory, but products with this certification are much safer than those without. We’d better choose products with UL, ETL, or CSA certification, or at least choose products made of UL, ETL, or CSA listed components.