Pigs and Darts for Coiled Tubing


6. Pigs & Darts for Coiled Tubing

We have developed quite a range of different pigs over the years, so a summary in approximate order of increasing toughness explains them. *Please click the thumbnail images for the catalogue listings.*

		6.1. Foam wiper type P/N 13303x series. The softest. Made of green foam with chevrons. Mostly intended for ensuring a film of anti-rust treatment is applied in the coil. So not intended to scrape all fluid cleanly off. Maximum operating pressure 2000psi.

		6.2. Foam cylinder type P/N 12303x series. Same foam, but white, and because cylindrical, much tougher. Any use requiring displacement of fluid. Probably the best for minimum bypass. Will clean off soft deposits, but foam will flex to move past stuck deposits. Maximum operating pressure 2000psi.

		6.3. Wiper dart type P/N 1240xx series. In orange PU elastomer. Polychevron design. Tougher still. Also for fluid displacement and rather better at cleaning out. There is probably not a lot of difference between the effectiveness of 2. & 3. and it is noticeable from sales patterns that some people and companies prefer one while others prefer another. Some latched on to darts early and so used the chevron elastomer, which was available a year or two before the foam was established.

		6.4. Scraper dart type P/N 120xxx series. In the same but green PU elastomer. Design has 5 discs of PU on a central core ie much thicker (approx 1/4") lips. Scrapes better than above types. Passing one of these through after any of the above gets yet more rubbish scraped from tubing walls. But previously less popular with operatives because harder to insert, so we are now providing a redesigned front end to make this easier.

		6.5. Turbo type P/N 136xxx series. Based on Kevlar reinforced bonded abrasive. 'Propeller' blade design mounted on a central core. The propellers do not turn individually but cause turbulent flow as the dart progresses through the tubing, spinning the whole dart. a) Coarse for primary clean of harder deposits. b) Polisher for a finer finish. Sized for the tubing and its max wall thickness, so these are made up as required, not stocked. The OD and the thickness of the Kevlar propeller are also different for the Coarse and Polish grades. Effective, and ideal in parallel tubing. Since most tubing is tapered we also developed the following.

		6.6. Scraper, Abrasive Polish SiC Foam type P/N 12103x series. Consists of the same foam as 2. with a fine grade silicon carbide moulded to the wall of the cylinder. The earlier mesh type we used to offer proved difficult for us to make consistently. We have replaced this with the same design as below but with fine grade SiC; this gives better wall contact than the mesh. Polish darts are colour coded green. Maximum operating pressure 2000psi.

		6.7. Scraper, Abrasive Coarse SiC Foam type P/N 12105x series. Foam cylinder with a coarse SiC bonded in helical strips. Scrapes off hard deposits with some bypass allowing flushing to clean working face. Coarse darts are differentiated by colour coded orange caps. Apart from good wall contact and good abrasion giving good cleaning, the foam core means that these two last will squeeze into the top heavy wall and expand slightly into the lower thinner wall in taper strings and still be as effective. We think this is the best for the heaviest duty. Maximum operating pressure 2000psi.

6. Pigs & Darts for Coiled Tubing